Heliophysics Decadal Survey
White Paper Concepts

The purpose of this site is to allow members of the heliophysics science community to inform one another of intent to submit a white paper as part of the solar and space physics decadal survey. These white paper concepts are for the decadal survey itself and are not for the Heliophysics 2050 Workshop; the Heliophysics 2050 Workshop submissions will not be ported to this webpage.

This site is for information only and is not part of the National Academies' activities. Listing a white paper concept here does not commit the author to submitting a white paper to the Decadal Survey, and an individual is not required to list a white paper here in order to submit it for the Decadal Survey.

Note: When submitting a white paper concept, if you are inviting feedback or input from interested community members, please end your white paper summary with “REQUESTED INPUT: [description]” and any additional contact information.

Click here to submit a white paper concept.

Link to NASA Heliophysics Division Decadal Survey page

Link to NASA-supported mission concept studies (coming). [Heliophysics Mission Concept Studies solicitation]

Please refer any questions to MeetingInfo@hou.usra.edu.


Jump to a specific topic:


Science (including enabling measurements)


Solar science

Title

Description

Authorship

Contact

Title

Accessibility and inclusive development for solar flares radiation exposure

Description

The solar flares radiation exposure causes impacts and effects on the health of the human individuals who are exposed to this solar energy. This leads to the creation of new innovations built in the subject areas of Accessibility and inclusive development in the platform channels of information and communication technologies and artificial intelligence and robotics. Also this Innovative ideology is extracted to a variety of different sectors, namely, the food systems and the smart agriculture. An innovative ideology product solution is provided in the website URL and link which is mentioned here below:- https://solarflaresandthefoodcrops.webnode.in

Authorship

Ashwini Sathnur, NASA SBAG working group Member

Contact

Ashwini Sathnur (ashwiniashis@yahoo.com)

Title

The Case for Broadening the Scope of Heliophysics

Description

Moving forward, hopefully starting with the next Decadal Survey and certainly by 2050, the solar and space physics community should focus emphasis on the general and fundamental importance and excitement of its science with a new mindset: Heliophysics is a fundamental science discipline that is interwoven with planetary science, astrophysics, geoscience, and laboratory plasma physics. It is the study of the very nature of plasmas throughout space, originating with our own Sun and heliosphere and extending to planetary atmospheres and magnetospheres, stellar atmospheres and astrospheres, interstellar space, and more exotic magnetized plasma regimes like pulsars, black holes, and supernovae.

Authorship

Ian Cohen, Matina Gkioulidou, Drew Turner, Romina Nikoukar, Joe Westlake (JHU/APL); Aleida Higginson (NASA/GSFC); Ryan McGranaghan (ASTRA); Gordon Emslie (WKU); Dan Baker (LASP); and Harlan Spence (UNH)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

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Heliospheric science

Title

Description

Authorship

Contact

Title

Accessibility and inclusive development for solar flares radiation exposure

Description

The solar flares radiation exposure causes impacts and effects on the health of the human individuals who are exposed to this solar energy. This leads to the creation of new innovations built in the subject areas of Accessibility and inclusive development in the platform channels of information and communication technologies and artificial intelligence and robotics. Also this Innovative ideology is extracted to a variety of different sectors, namely, the food systems and the smart agriculture. An innovative ideology product solution is provided in the website URL and link which is mentioned here below:- https://solarflaresandthefoodcrops.webnode.in

Authorship

Ashwini Sathnur, NASA SBAG working group Member

Contact

Ashwini Sathnur (ashwiniashis@yahoo.com)

Title

Expanding the Realm of Solar & Space Physics: Exploration of the Outer Heliosphere and Local Interstellar Medium

Description

During its evolutionary journey through the galaxy, the Sun and its protective heliosphere have encountered widely different environments that have all helped form the system we live in, and soon our star will enter a completely new region of interstellar space. The orders-of-magnitude varying properties of interstellar plasma and gas are responsible for an extreme range of sizes and shapes of the global heliosphere throughout its history. This, in turn, has had dramatic consequence for the penetration interstellar dust and galactic cosmic rays that have affected several crucial aspects of elemental and isotopic abundances, atmospheric evolution and conditions for habitability. Despite the importance for the heliosphere and other astrospheres, the interaction mechanisms at the heliospheric boundary could not be understood by the limited Voyager payloads and represent a new regime of space physics. At the same time, the lack of direct access to pristine interstellar material has prevented progress in understanding the physics of the interstellar clouds and galactic evolution. A new science frontier awaits heliophysics by exploring the outer heliosphere, its boundary and beyond out to 400-1000 AU, a region now being made accessible within realistic mission design lifetimes by the increasing availability of large launch vehicles.

Authorship

Brandt, P. C. + 88 co-authors

Contact

Pontus C. Brandt (pontus.brandt@jhuapl.edu)

Title

Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Description

NASA’s heliospheric division studies “the Sun, the heliosphere, and Earth’s magnetosphere and... universal plasma phenomena”. We will argue that Jupiter's radiation belts, magnetosphere, and near-space environment should be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s magnetosphere covers all universal processes called out in the 2013 Decadal. Space plasma physics at planetary systems is much more relevant to the defined focus of NASA’s Heliophysics division than for the core sciences of the planetary division. Jupiter’s giant magnetosphere hosts a wealth of particle species and charges subject to processes that can be studied with less ambiguity relative to Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to investigate a wide range of space plasma processes. Its magnetosphere continuously accelerates particles to higher energies than what is even reached during extreme space weather events. Jupiter covers such an immense parameter range in particle energies, magnetic field, and waves that it can bridge the in-situ study of magnetospheres and the remote observation of extrasolar systems like supernova remnants.

Authorship

everybody who is interested

Contact

Peter Kollmann (Peter.Kollmann@jhuapl.edu)

Title

The Case for Broadening the Scope of Heliophysics

Description

Moving forward, hopefully starting with the next Decadal Survey and certainly by 2050, the solar and space physics community should focus emphasis on the general and fundamental importance and excitement of its science with a new mindset: Heliophysics is a fundamental science discipline that is interwoven with planetary science, astrophysics, geoscience, and laboratory plasma physics. It is the study of the very nature of plasmas throughout space, originating with our own Sun and heliosphere and extending to planetary atmospheres and magnetospheres, stellar atmospheres and astrospheres, interstellar space, and more exotic magnetized plasma regimes like pulsars, black holes, and supernovae.

Authorship

Ian Cohen, Matina Gkioulidou, Drew Turner, Romina Nikoukar, Joe Westlake (JHU/APL); Aleida Higginson (NASA/GSFC); Ryan McGranaghan (ASTRA); Gordon Emslie (WKU); Dan Baker (LASP); and Harlan Spence (UNH)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

Title

The potential of the Interstellar Probe for measuring in-situ interstellar neutrals

Description

A near-term Interstellar Probe would enable in-situ measurements of the interstellar medium all the way from the Earth to the heliosheath and beyond the reaches of the heliopause. These revolutionary measurements would reveal how the interstellar medium is filtrated and deflected by our heliosphere and the chemical and isotopical composition of the unperturbed interstellar medium itself.

Authorship

Andre Galli, Seth Redfield, Elena Provornikova, Harald Kucharek, Paweł Swaczyna, Justyna M. Sokół, Marzena A. Kubiak, Ben L. Alterman

Contact

Andre Galli (andre.galli@space.unibe.ch)

Title

The role of kappa distributions in Space Thermodynamics

Description

Classical collisional particle systems residing in thermal equilibrium have their particle velocity/energy distribution function stabilized into a Maxwell-Boltzmann distribution. On the contrary, space plasmas are collisionless particle systems residing in stationary states characterized by a non-Maxwellian behavior, typically described by kappa distributions. These distributions have become increasingly widespread across the physics of space plasma processes, describing particles in the heliosphere, from the solar wind and planetary magnetospheres to the heliosheath and beyond, the interstellar and intergalactic plasmas. A breakthrough in the field came with the connection of kappa distributions with statistical mechanics and thermodynamics. In particular, (i) maximize the entropy of nonextensive statistical mechanics under the constraints of canonical ensemble, (ii) characterize particle systems exchanging heat with each other eventually stabilized at a non-classical version of thermal equilibrium, and (iii) constitute the unique description of particle energies consistent with polytropic behavior.

Authorship

George Livadiotis

Contact

George Livadiotis (glivadiotis@swri.edu)

Title

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium

Description

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium Jeffrey L. Linsky1 and Seth Redfield2 1JILA, University of Colorado and NIST, Boulder, CO 80309-0440, USA 2Astronomy Department and Van Vleck Observatory, Wesleyan University, Middletown, CT 06459-0123, USA ABSTRACT Our understanding of the outer heliosphere is becoming clearer from direct measurements by the Voyager spacecraft and theoretical models, but what lies beyond the heliopause in the Very Local Interstellar Medium (VLISM) and beyond in the pristine Local Interstellar Medium (LISM) is a new frontier of heliospheric research. This white paper for the Heliophysics 2050 Workshop describes critical questions concerning the plasma and magnetic field and physical processes in the VLISM and LISM. 1. THE PRESENT PICTURE The heliosphere is the interface between our solar system and the rest of the galaxy. Measurements using both heliospheric and astronomical techniques are required to fully understand the physical interactions and morphology of this interface. Measurements from both perspectives are needed to apply out knowledge of the heliosphere to analogous structures around other nearby stars, many of which host habitable planets, and to evaluate how the heliosphere has evolved and influenced the habitability of solar system planets. The Voyagers passed the termnation shock (TS) at 94 AU (V1) and 84 AU (V2) and traversed the heliopause (HP) at 122 AU (V1) and 119 AU (V2). Beyond the HP, interstellar plasma is modified by the inclusion of pickup ions and anomalous cosmic rays created in the TS and heliosheath that leak into the VLISM through the HP. This region was called the Very Local Interstellar Medium (VLISM) by Zank (2015). Inside the VLISM, charge exchange reactions between inflowing hydrogen atoms and energetic solar wind protons create the “hydrogen wall” (HW) where hydrogen atoms are piled up (increased density), heated, and slowed down relative to the inflow speed of neutral hydrogen from the pristine LISM. Hydrogen wall absorption in the Lyman-α line measures solar or stellar mass-loss rates. Figure 1 shows a heliosphere model where the HW is seen as a neutral hydrogen density enhancement outside of the HP. In models by Zank et al. (2013), the maximum density in the HW occurs near 300 AU and extends outward to 400–600 AU depending on the local magnetic field strength. The only direct measurements of the inflowing VLISM gas are the neutral helium atoms that penetrate the heliosphere relatively unscathed by charge exchange reactions and neutral hydrogen atoms modified by charge exchange reactions and identified by backscattered Lyman-α radiation. Beyond the VLISM, perhaps 500–700 AU from the Sun, is the pristine Local Interstellar Medium (LISM) for which there are no direct measurements. We have only a crude understanding of the LISM based only on theory and remote measurements. 2. VLISM SCIENCE QUESTIONS Models of the HWand VLISM computed with a MHD plasma – kinetic hydrogen code by 2 Figure 1. The heliosphere model computed by Richardson & Stone (2009). The top half shows the temperature structure. The bottom half shows the neutral hydrogen density. The HW is between 200 and 250 AU in the upwind direction. Zank et al. (2013) show that the VLISM magnetic field plays a critical role in determining (i) whether the decelerating LISM plasma has a bow shock or a bow wave, (ii) the amount of heating in the VLISM, and (iii) the neutral H column density density in the HW. Absorption in the Lyman-α line is best described by their model with a VLISM magnetic field of 3 μG, the same value inferred from observations of the IBEX ribbon (Zirnstein et al 2016). Other processes, known and unknown, shape the VLISM plasma. For example, pickup ions produced near the TS and accelerated ions (anomalous cosmic rays) dominate the heliosheath pressure. Gloeckler & Fisk (2016) estimate the total pressure just beyond the HP by balancing the total pressure on both sides of the HP. They estimate that the total gas pressure pressure just beyond the HP as P(tot)/k = 25, 855 Kcm−3, whereas the total gas and magnetic pressure in the inner LISM is only 5,565 Kcm−3 (Frisch et al. 2011), a factor of 4–5 times smaller. To balance the total pressure, the magnetic field just outside of the HP should be about 8 μG, which is far larger than measured by V1 and somewhat larger than measured by V2. On this basis V1 and V2 have not yet have crossed the HP. Direct measurements of the thermal and nonthermal plasma and magnetic fields are needed to understand the VLISM and test the models. In particular, we need to know how far out solar energetic neutrals and ions extend and the length scales for charge exchange and thermalization processes in order to determine where the VLISM ends and the pristine LISM begins. 3. LISM SCIENCE QUESTIONS Absorption line measurements of interstellar gas in the sightlines to nearby stars are the primary data set used to construct models of the LISM. Analysis of HST ultraviolet spectra yield line of sight average measurements of elemental abundances, ionization states, and velocity structure between the Sun and stars. Redfield & Linsky identified 15 clouds in the LISM by common velocity vectors towards stars. Each of these clouds has a mean temperature of 5,000–10,000 K. Linsky et al. (2019) showed that four clouds (see Figure 2) are very near the outer heliosphere. Local Interstellar Cloud (LIC) absorption covers less than half the sky, indicating that the gas entering the VLISM and heliosphere may be at the edge LIC with somewhat different properties than in the LIC center. The neutral hydrogen density in the LIC had been estimated to be 0.195 cm−3 (Slavin & Frisch 2008) or about 0.12 cm−3 on the basis V2 and Cassini/INCA measurements (Dialynas et al. 2019). However, these are rough estimates of the mean hydrogen density in only one of the LISM clouds. Direct measurements of neutrals, electrons, and ions are needed to study the properties of the LISM. 3 Figure 2. Morphologies of the four partially ionized LISM clouds that are near the outer heliosphere: the LIC (red), which lies in front of ǫ Eri (3.2 pc), the G cloud (brown), which lies in front of α Cen (1.32 pc), the Blue cloud (dark blue), which lies in front of Sirius (2.64 pc), and the Aql cloud (green), which lies in front of 61 Cyg (3.5 pc). The plot is in Galactic coordinates with the Galactic Center direction in the center. The LIC upwind direction is indicated by the circled-cross symbol near l = 15◦ and b = +20◦, and the upwind directions of the other clouds have similar marks. The heliosphere is now exiting the LIC in the direction of the neighboring G cloud. Upper limits on the amount of interstellar Mg II absorption in this direction predict that the heliosphere will leave the LIC in less than 1900 years and perhaps this year. This would be a major event. Will the heliosphere directly enter the G cloud or a photoionized boundary layer with little neutral hydrogen? The size of the heliosphere and the composition of its plasma will change in either scenario. The EUVE satellite discovered that the star ǫ CMa (ecliptic coordinates λ = 111◦, β = −51◦ and distance 124 pc) is the the brightest source of extreme-UV radiation. EUV photons from ǫ CMa produce a very large photoionized region (called a Str¨omgren sphere) that surrounds the LISM warm clouds and the partially ionized Str¨omgren shells on the outer regions of the LISM clouds. EUV radiation from ǫ CMa photoionizes neutral hydrogen producing very low neutral hydrogen column density in this direction called the “hydrogen hole”. The role of photoionization must be tested. Magnetic fields will be important in shaping the morphology of clouds if the magnetic pressure exceeds the gas pressure, which would occur if BLISM > 3μG. Stronger magnetic fields just beyond the HP observed by V2 (Dialynas et al.(2019) suggest that magnetic fields may dominate the pressure in the LISM clouds. The very low density plasma in the LISM may include non-thermal particles that dominate the total pressure. Supernovae in the nearby Scorpio-Centaurus Association have occured as recently as a few million years ago and their shock waves produced high ionization in the LISM that may still be recombining. The ram pressure of supernovae shocks can dominate other sources of pressure in the simulations of Berghofer & Breitschwerdt (2002). Recent models of the velocity distribution of plasma in the outer heliosphere include non-thermal components (Swaczya et al. 2019). Future analysis of LISM absorption line profiles should test for high velocity tails using kappa distributions. The relative importance of these and potentially other sources of ionization and morphology in the LISM need to be understood. Direct measurements of thermal and non-thermal plasma and magnetic fields can accomplish this. References: Berghofer & Breitschwerdt (2002) Astron. Astrphys. 390, 299. Dialynas et al. (2019) Geophys. Res. Let. 46, 7911. Frisch et al. (2011) ARAA 49, 237. Gloeckler & Fisk (2016) ApJ 833, 290. Linsky et al. (2019) ApJ 886, 41. Redfield & Linsky (2008) ApJ 673, 283. Richardson & Stone (2009) Space Sci. Rev 143, 7. Swaczyna et al. (2019) ApJ 871, 254. Zank et al. (2013) ApJ 763, 20. Zirnstein et al. (2016) ApJ 818, L18.

Authorship

Jeffrey L. Linsky and Seth Redfield

Contact

Jeffrey Linsky (jlinsky@jila.colorado.edu)

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Magnetospheric science

Title

Description

Authorship

Contact

Title

Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Description

NASA’s heliospheric division studies “the Sun, the heliosphere, and Earth’s magnetosphere and... universal plasma phenomena”. We will argue that Jupiter's radiation belts, magnetosphere, and near-space environment should be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s magnetosphere covers all universal processes called out in the 2013 Decadal. Space plasma physics at planetary systems is much more relevant to the defined focus of NASA’s Heliophysics division than for the core sciences of the planetary division. Jupiter’s giant magnetosphere hosts a wealth of particle species and charges subject to processes that can be studied with less ambiguity relative to Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to investigate a wide range of space plasma processes. Its magnetosphere continuously accelerates particles to higher energies than what is even reached during extreme space weather events. Jupiter covers such an immense parameter range in particle energies, magnetic field, and waves that it can bridge the in-situ study of magnetospheres and the remote observation of extrasolar systems like supernova remnants.

Authorship

everybody who is interested

Contact

Peter Kollmann (Peter.Kollmann@jhuapl.edu)

Title

The Case for Broadening the Scope of Heliophysics

Description

Moving forward, hopefully starting with the next Decadal Survey and certainly by 2050, the solar and space physics community should focus emphasis on the general and fundamental importance and excitement of its science with a new mindset: Heliophysics is a fundamental science discipline that is interwoven with planetary science, astrophysics, geoscience, and laboratory plasma physics. It is the study of the very nature of plasmas throughout space, originating with our own Sun and heliosphere and extending to planetary atmospheres and magnetospheres, stellar atmospheres and astrospheres, interstellar space, and more exotic magnetized plasma regimes like pulsars, black holes, and supernovae.

Authorship

Ian Cohen, Matina Gkioulidou, Drew Turner, Romina Nikoukar, Joe Westlake (JHU/APL); Aleida Higginson (NASA/GSFC); Ryan McGranaghan (ASTRA); Gordon Emslie (WKU); Dan Baker (LASP); and Harlan Spence (UNH)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

Title

The role of kappa distributions in Space Thermodynamics

Description

Classical collisional particle systems residing in thermal equilibrium have their particle velocity/energy distribution function stabilized into a Maxwell-Boltzmann distribution. On the contrary, space plasmas are collisionless particle systems residing in stationary states characterized by a non-Maxwellian behavior, typically described by kappa distributions. These distributions have become increasingly widespread across the physics of space plasma processes, describing particles in the heliosphere, from the solar wind and planetary magnetospheres to the heliosheath and beyond, the interstellar and intergalactic plasmas. A breakthrough in the field came with the connection of kappa distributions with statistical mechanics and thermodynamics. In particular, (i) maximize the entropy of nonextensive statistical mechanics under the constraints of canonical ensemble, (ii) characterize particle systems exchanging heat with each other eventually stabilized at a non-classical version of thermal equilibrium, and (iii) constitute the unique description of particle energies consistent with polytropic behavior.

Authorship

George Livadiotis

Contact

George Livadiotis (glivadiotis@swri.edu)

Title

Towards a Better Understanding of the Causes and Consequences of Geomagnetic Perturbations in 2050

Description

Disturbances in the magnetic field at the Earth’s surface are at the center of Heliophysics and Space Weather research: remote sensing magnetosphere-ionosphere current systems, construction of geomagnetic indices used for space weather forecasts and model validation, monitoring of geoelectric fields and related Geomagnetically Induced Currents (GIC). The purpose of this white paper is to highlight future research, instrumentation, and community/inter-agency efforts that are needed to improve our understanding of the causes and consequences of these perturbations.

Authorship

Michael Hartinger +10 co-authors

Contact

Michael Hartinger (mhartinger@spacescience.org)

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ITM science

Title

Description

Authorship

Contact

Title

Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Description

NASA’s heliospheric division studies “the Sun, the heliosphere, and Earth’s magnetosphere and... universal plasma phenomena”. We will argue that Jupiter's radiation belts, magnetosphere, and near-space environment should be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s magnetosphere covers all universal processes called out in the 2013 Decadal. Space plasma physics at planetary systems is much more relevant to the defined focus of NASA’s Heliophysics division than for the core sciences of the planetary division. Jupiter’s giant magnetosphere hosts a wealth of particle species and charges subject to processes that can be studied with less ambiguity relative to Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to investigate a wide range of space plasma processes. Its magnetosphere continuously accelerates particles to higher energies than what is even reached during extreme space weather events. Jupiter covers such an immense parameter range in particle energies, magnetic field, and waves that it can bridge the in-situ study of magnetospheres and the remote observation of extrasolar systems like supernova remnants.

Authorship

everybody who is interested

Contact

Peter Kollmann (Peter.Kollmann@jhuapl.edu)

Title

The Case for Broadening the Scope of Heliophysics

Description

Moving forward, hopefully starting with the next Decadal Survey and certainly by 2050, the solar and space physics community should focus emphasis on the general and fundamental importance and excitement of its science with a new mindset: Heliophysics is a fundamental science discipline that is interwoven with planetary science, astrophysics, geoscience, and laboratory plasma physics. It is the study of the very nature of plasmas throughout space, originating with our own Sun and heliosphere and extending to planetary atmospheres and magnetospheres, stellar atmospheres and astrospheres, interstellar space, and more exotic magnetized plasma regimes like pulsars, black holes, and supernovae.

Authorship

Ian Cohen, Matina Gkioulidou, Drew Turner, Romina Nikoukar, Joe Westlake (JHU/APL); Aleida Higginson (NASA/GSFC); Ryan McGranaghan (ASTRA); Gordon Emslie (WKU); Dan Baker (LASP); and Harlan Spence (UNH)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

Title

Towards a Better Understanding of the Causes and Consequences of Geomagnetic Perturbations in 2050

Description

Disturbances in the magnetic field at the Earth’s surface are at the center of Heliophysics and Space Weather research: remote sensing magnetosphere-ionosphere current systems, construction of geomagnetic indices used for space weather forecasts and model validation, monitoring of geoelectric fields and related Geomagnetically Induced Currents (GIC). The purpose of this white paper is to highlight future research, instrumentation, and community/inter-agency efforts that are needed to improve our understanding of the causes and consequences of these perturbations.

Authorship

Michael Hartinger +10 co-authors

Contact

Michael Hartinger (mhartinger@spacescience.org)

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Interdisciplinary/system science

Title

Description

Authorship

Contact

Title

Expanding the Realm of Solar & Space Physics: Exploration of the Outer Heliosphere and Local Interstellar Medium

Description

During its evolutionary journey through the galaxy, the Sun and its protective heliosphere have encountered widely different environments that have all helped form the system we live in, and soon our star will enter a completely new region of interstellar space. The orders-of-magnitude varying properties of interstellar plasma and gas are responsible for an extreme range of sizes and shapes of the global heliosphere throughout its history. This, in turn, has had dramatic consequence for the penetration interstellar dust and galactic cosmic rays that have affected several crucial aspects of elemental and isotopic abundances, atmospheric evolution and conditions for habitability. Despite the importance for the heliosphere and other astrospheres, the interaction mechanisms at the heliospheric boundary could not be understood by the limited Voyager payloads and represent a new regime of space physics. At the same time, the lack of direct access to pristine interstellar material has prevented progress in understanding the physics of the interstellar clouds and galactic evolution. A new science frontier awaits heliophysics by exploring the outer heliosphere, its boundary and beyond out to 400-1000 AU, a region now being made accessible within realistic mission design lifetimes by the increasing availability of large launch vehicles.

Authorship

Brandt, P. C. + 88 co-authors

Contact

Pontus C. Brandt (pontus.brandt@jhuapl.edu)

Title

Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Description

NASA’s heliospheric division studies “the Sun, the heliosphere, and Earth’s magnetosphere and... universal plasma phenomena”. We will argue that Jupiter's radiation belts, magnetosphere, and near-space environment should be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s magnetosphere covers all universal processes called out in the 2013 Decadal. Space plasma physics at planetary systems is much more relevant to the defined focus of NASA’s Heliophysics division than for the core sciences of the planetary division. Jupiter’s giant magnetosphere hosts a wealth of particle species and charges subject to processes that can be studied with less ambiguity relative to Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to investigate a wide range of space plasma processes. Its magnetosphere continuously accelerates particles to higher energies than what is even reached during extreme space weather events. Jupiter covers such an immense parameter range in particle energies, magnetic field, and waves that it can bridge the in-situ study of magnetospheres and the remote observation of extrasolar systems like supernova remnants.

Authorship

everybody who is interested

Contact

Peter Kollmann (Peter.Kollmann@jhuapl.edu)

Title

The Case for Broadening the Scope of Heliophysics

Description

Moving forward, hopefully starting with the next Decadal Survey and certainly by 2050, the solar and space physics community should focus emphasis on the general and fundamental importance and excitement of its science with a new mindset: Heliophysics is a fundamental science discipline that is interwoven with planetary science, astrophysics, geoscience, and laboratory plasma physics. It is the study of the very nature of plasmas throughout space, originating with our own Sun and heliosphere and extending to planetary atmospheres and magnetospheres, stellar atmospheres and astrospheres, interstellar space, and more exotic magnetized plasma regimes like pulsars, black holes, and supernovae.

Authorship

Ian Cohen, Matina Gkioulidou, Drew Turner, Romina Nikoukar, Joe Westlake (JHU/APL); Aleida Higginson (NASA/GSFC); Ryan McGranaghan (ASTRA); Gordon Emslie (WKU); Dan Baker (LASP); and Harlan Spence (UNH)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

Title

Why and How to Increase Cross-Divisional Opportunities

Description

Robotic space exploration, especially to far reaches of the solar system, is by its very nature difficult and expensive. As such, it behooves the entire space science community to work collaboratively to maximize the scientific return of missions, regardless of the primary funding Division. In the future, NASA should offer increased support and more opportunities enabling cross-Divisional science.

Authorship

Ian Cohen, Abigail Rymer, Drew Turner, Matina Gkioulidou, George Clark, Peter Kollmann, Sarah Vines, Robert Allen, Joseph Westlake, Romina Nikoukar (JHU/APL)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

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Outer heliosphere

Title

Description

Authorship

Contact

Title

Expanding the Realm of Solar & Space Physics: Exploration of the Outer Heliosphere and Local Interstellar Medium

Description

During its evolutionary journey through the galaxy, the Sun and its protective heliosphere have encountered widely different environments that have all helped form the system we live in, and soon our star will enter a completely new region of interstellar space. The orders-of-magnitude varying properties of interstellar plasma and gas are responsible for an extreme range of sizes and shapes of the global heliosphere throughout its history. This, in turn, has had dramatic consequence for the penetration interstellar dust and galactic cosmic rays that have affected several crucial aspects of elemental and isotopic abundances, atmospheric evolution and conditions for habitability. Despite the importance for the heliosphere and other astrospheres, the interaction mechanisms at the heliospheric boundary could not be understood by the limited Voyager payloads and represent a new regime of space physics. At the same time, the lack of direct access to pristine interstellar material has prevented progress in understanding the physics of the interstellar clouds and galactic evolution. A new science frontier awaits heliophysics by exploring the outer heliosphere, its boundary and beyond out to 400-1000 AU, a region now being made accessible within realistic mission design lifetimes by the increasing availability of large launch vehicles.

Authorship

Brandt, P. C. + 88 co-authors

Contact

Pontus C. Brandt (pontus.brandt@jhuapl.edu)

Title

Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Description

NASA’s heliospheric division studies “the Sun, the heliosphere, and Earth’s magnetosphere and... universal plasma phenomena”. We will argue that Jupiter's radiation belts, magnetosphere, and near-space environment should be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s magnetosphere covers all universal processes called out in the 2013 Decadal. Space plasma physics at planetary systems is much more relevant to the defined focus of NASA’s Heliophysics division than for the core sciences of the planetary division. Jupiter’s giant magnetosphere hosts a wealth of particle species and charges subject to processes that can be studied with less ambiguity relative to Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to investigate a wide range of space plasma processes. Its magnetosphere continuously accelerates particles to higher energies than what is even reached during extreme space weather events. Jupiter covers such an immense parameter range in particle energies, magnetic field, and waves that it can bridge the in-situ study of magnetospheres and the remote observation of extrasolar systems like supernova remnants.

Authorship

everybody who is interested

Contact

Peter Kollmann (Peter.Kollmann@jhuapl.edu)

Title

The Case for Broadening the Scope of Heliophysics

Description

Moving forward, hopefully starting with the next Decadal Survey and certainly by 2050, the solar and space physics community should focus emphasis on the general and fundamental importance and excitement of its science with a new mindset: Heliophysics is a fundamental science discipline that is interwoven with planetary science, astrophysics, geoscience, and laboratory plasma physics. It is the study of the very nature of plasmas throughout space, originating with our own Sun and heliosphere and extending to planetary atmospheres and magnetospheres, stellar atmospheres and astrospheres, interstellar space, and more exotic magnetized plasma regimes like pulsars, black holes, and supernovae.

Authorship

Ian Cohen, Matina Gkioulidou, Drew Turner, Romina Nikoukar, Joe Westlake (JHU/APL); Aleida Higginson (NASA/GSFC); Ryan McGranaghan (ASTRA); Gordon Emslie (WKU); Dan Baker (LASP); and Harlan Spence (UNH)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

Title

The potential of the Interstellar Probe for measuring in-situ interstellar neutrals

Description

A near-term Interstellar Probe would enable in-situ measurements of the interstellar medium all the way from the Earth to the heliosheath and beyond the reaches of the heliopause. These revolutionary measurements would reveal how the interstellar medium is filtrated and deflected by our heliosphere and the chemical and isotopical composition of the unperturbed interstellar medium itself.

Authorship

Andre Galli, Seth Redfield, Elena Provornikova, Harald Kucharek, Paweł Swaczyna, Justyna M. Sokół, Marzena A. Kubiak, Ben L. Alterman

Contact

Andre Galli (andre.galli@space.unibe.ch)

Title

The role of kappa distributions in Space Thermodynamics

Description

Classical collisional particle systems residing in thermal equilibrium have their particle velocity/energy distribution function stabilized into a Maxwell-Boltzmann distribution. On the contrary, space plasmas are collisionless particle systems residing in stationary states characterized by a non-Maxwellian behavior, typically described by kappa distributions. These distributions have become increasingly widespread across the physics of space plasma processes, describing particles in the heliosphere, from the solar wind and planetary magnetospheres to the heliosheath and beyond, the interstellar and intergalactic plasmas. A breakthrough in the field came with the connection of kappa distributions with statistical mechanics and thermodynamics. In particular, (i) maximize the entropy of nonextensive statistical mechanics under the constraints of canonical ensemble, (ii) characterize particle systems exchanging heat with each other eventually stabilized at a non-classical version of thermal equilibrium, and (iii) constitute the unique description of particle energies consistent with polytropic behavior.

Authorship

George Livadiotis

Contact

George Livadiotis (glivadiotis@swri.edu)

Title

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium

Description

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium Jeffrey L. Linsky1 and Seth Redfield2 1JILA, University of Colorado and NIST, Boulder, CO 80309-0440, USA 2Astronomy Department and Van Vleck Observatory, Wesleyan University, Middletown, CT 06459-0123, USA ABSTRACT Our understanding of the outer heliosphere is becoming clearer from direct measurements by the Voyager spacecraft and theoretical models, but what lies beyond the heliopause in the Very Local Interstellar Medium (VLISM) and beyond in the pristine Local Interstellar Medium (LISM) is a new frontier of heliospheric research. This white paper for the Heliophysics 2050 Workshop describes critical questions concerning the plasma and magnetic field and physical processes in the VLISM and LISM. 1. THE PRESENT PICTURE The heliosphere is the interface between our solar system and the rest of the galaxy. Measurements using both heliospheric and astronomical techniques are required to fully understand the physical interactions and morphology of this interface. Measurements from both perspectives are needed to apply out knowledge of the heliosphere to analogous structures around other nearby stars, many of which host habitable planets, and to evaluate how the heliosphere has evolved and influenced the habitability of solar system planets. The Voyagers passed the termnation shock (TS) at 94 AU (V1) and 84 AU (V2) and traversed the heliopause (HP) at 122 AU (V1) and 119 AU (V2). Beyond the HP, interstellar plasma is modified by the inclusion of pickup ions and anomalous cosmic rays created in the TS and heliosheath that leak into the VLISM through the HP. This region was called the Very Local Interstellar Medium (VLISM) by Zank (2015). Inside the VLISM, charge exchange reactions between inflowing hydrogen atoms and energetic solar wind protons create the “hydrogen wall” (HW) where hydrogen atoms are piled up (increased density), heated, and slowed down relative to the inflow speed of neutral hydrogen from the pristine LISM. Hydrogen wall absorption in the Lyman-α line measures solar or stellar mass-loss rates. Figure 1 shows a heliosphere model where the HW is seen as a neutral hydrogen density enhancement outside of the HP. In models by Zank et al. (2013), the maximum density in the HW occurs near 300 AU and extends outward to 400–600 AU depending on the local magnetic field strength. The only direct measurements of the inflowing VLISM gas are the neutral helium atoms that penetrate the heliosphere relatively unscathed by charge exchange reactions and neutral hydrogen atoms modified by charge exchange reactions and identified by backscattered Lyman-α radiation. Beyond the VLISM, perhaps 500–700 AU from the Sun, is the pristine Local Interstellar Medium (LISM) for which there are no direct measurements. We have only a crude understanding of the LISM based only on theory and remote measurements. 2. VLISM SCIENCE QUESTIONS Models of the HWand VLISM computed with a MHD plasma – kinetic hydrogen code by 2 Figure 1. The heliosphere model computed by Richardson & Stone (2009). The top half shows the temperature structure. The bottom half shows the neutral hydrogen density. The HW is between 200 and 250 AU in the upwind direction. Zank et al. (2013) show that the VLISM magnetic field plays a critical role in determining (i) whether the decelerating LISM plasma has a bow shock or a bow wave, (ii) the amount of heating in the VLISM, and (iii) the neutral H column density density in the HW. Absorption in the Lyman-α line is best described by their model with a VLISM magnetic field of 3 μG, the same value inferred from observations of the IBEX ribbon (Zirnstein et al 2016). Other processes, known and unknown, shape the VLISM plasma. For example, pickup ions produced near the TS and accelerated ions (anomalous cosmic rays) dominate the heliosheath pressure. Gloeckler & Fisk (2016) estimate the total pressure just beyond the HP by balancing the total pressure on both sides of the HP. They estimate that the total gas pressure pressure just beyond the HP as P(tot)/k = 25, 855 Kcm−3, whereas the total gas and magnetic pressure in the inner LISM is only 5,565 Kcm−3 (Frisch et al. 2011), a factor of 4–5 times smaller. To balance the total pressure, the magnetic field just outside of the HP should be about 8 μG, which is far larger than measured by V1 and somewhat larger than measured by V2. On this basis V1 and V2 have not yet have crossed the HP. Direct measurements of the thermal and nonthermal plasma and magnetic fields are needed to understand the VLISM and test the models. In particular, we need to know how far out solar energetic neutrals and ions extend and the length scales for charge exchange and thermalization processes in order to determine where the VLISM ends and the pristine LISM begins. 3. LISM SCIENCE QUESTIONS Absorption line measurements of interstellar gas in the sightlines to nearby stars are the primary data set used to construct models of the LISM. Analysis of HST ultraviolet spectra yield line of sight average measurements of elemental abundances, ionization states, and velocity structure between the Sun and stars. Redfield & Linsky identified 15 clouds in the LISM by common velocity vectors towards stars. Each of these clouds has a mean temperature of 5,000–10,000 K. Linsky et al. (2019) showed that four clouds (see Figure 2) are very near the outer heliosphere. Local Interstellar Cloud (LIC) absorption covers less than half the sky, indicating that the gas entering the VLISM and heliosphere may be at the edge LIC with somewhat different properties than in the LIC center. The neutral hydrogen density in the LIC had been estimated to be 0.195 cm−3 (Slavin & Frisch 2008) or about 0.12 cm−3 on the basis V2 and Cassini/INCA measurements (Dialynas et al. 2019). However, these are rough estimates of the mean hydrogen density in only one of the LISM clouds. Direct measurements of neutrals, electrons, and ions are needed to study the properties of the LISM. 3 Figure 2. Morphologies of the four partially ionized LISM clouds that are near the outer heliosphere: the LIC (red), which lies in front of ǫ Eri (3.2 pc), the G cloud (brown), which lies in front of α Cen (1.32 pc), the Blue cloud (dark blue), which lies in front of Sirius (2.64 pc), and the Aql cloud (green), which lies in front of 61 Cyg (3.5 pc). The plot is in Galactic coordinates with the Galactic Center direction in the center. The LIC upwind direction is indicated by the circled-cross symbol near l = 15◦ and b = +20◦, and the upwind directions of the other clouds have similar marks. The heliosphere is now exiting the LIC in the direction of the neighboring G cloud. Upper limits on the amount of interstellar Mg II absorption in this direction predict that the heliosphere will leave the LIC in less than 1900 years and perhaps this year. This would be a major event. Will the heliosphere directly enter the G cloud or a photoionized boundary layer with little neutral hydrogen? The size of the heliosphere and the composition of its plasma will change in either scenario. The EUVE satellite discovered that the star ǫ CMa (ecliptic coordinates λ = 111◦, β = −51◦ and distance 124 pc) is the the brightest source of extreme-UV radiation. EUV photons from ǫ CMa produce a very large photoionized region (called a Str¨omgren sphere) that surrounds the LISM warm clouds and the partially ionized Str¨omgren shells on the outer regions of the LISM clouds. EUV radiation from ǫ CMa photoionizes neutral hydrogen producing very low neutral hydrogen column density in this direction called the “hydrogen hole”. The role of photoionization must be tested. Magnetic fields will be important in shaping the morphology of clouds if the magnetic pressure exceeds the gas pressure, which would occur if BLISM > 3μG. Stronger magnetic fields just beyond the HP observed by V2 (Dialynas et al.(2019) suggest that magnetic fields may dominate the pressure in the LISM clouds. The very low density plasma in the LISM may include non-thermal particles that dominate the total pressure. Supernovae in the nearby Scorpio-Centaurus Association have occured as recently as a few million years ago and their shock waves produced high ionization in the LISM that may still be recombining. The ram pressure of supernovae shocks can dominate other sources of pressure in the simulations of Berghofer & Breitschwerdt (2002). Recent models of the velocity distribution of plasma in the outer heliosphere include non-thermal components (Swaczya et al. 2019). Future analysis of LISM absorption line profiles should test for high velocity tails using kappa distributions. The relative importance of these and potentially other sources of ionization and morphology in the LISM need to be understood. Direct measurements of thermal and non-thermal plasma and magnetic fields can accomplish this. References: Berghofer & Breitschwerdt (2002) Astron. Astrphys. 390, 299. Dialynas et al. (2019) Geophys. Res. Let. 46, 7911. Frisch et al. (2011) ARAA 49, 237. Gloeckler & Fisk (2016) ApJ 833, 290. Linsky et al. (2019) ApJ 886, 41. Redfield & Linsky (2008) ApJ 673, 283. Richardson & Stone (2009) Space Sci. Rev 143, 7. Swaczyna et al. (2019) ApJ 871, 254. Zank et al. (2013) ApJ 763, 20. Zirnstein et al. (2016) ApJ 818, L18.

Authorship

Jeffrey L. Linsky and Seth Redfield

Contact

Jeffrey Linsky (jlinsky@jila.colorado.edu)

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Interstellar, stellar/solar, exoplanetary, habitability science

Title

Description

Authorship

Contact

Title

Accessibility and inclusive development for solar flares radiation exposure

Description

The solar flares radiation exposure causes impacts and effects on the health of the human individuals who are exposed to this solar energy. This leads to the creation of new innovations built in the subject areas of Accessibility and inclusive development in the platform channels of information and communication technologies and artificial intelligence and robotics. Also this Innovative ideology is extracted to a variety of different sectors, namely, the food systems and the smart agriculture. An innovative ideology product solution is provided in the website URL and link which is mentioned here below:- https://solarflaresandthefoodcrops.webnode.in

Authorship

Ashwini Sathnur, NASA SBAG working group Member

Contact

Ashwini Sathnur (ashwiniashis@yahoo.com)

Title

Expanding the Realm of Solar & Space Physics: Exploration of the Outer Heliosphere and Local Interstellar Medium

Description

During its evolutionary journey through the galaxy, the Sun and its protective heliosphere have encountered widely different environments that have all helped form the system we live in, and soon our star will enter a completely new region of interstellar space. The orders-of-magnitude varying properties of interstellar plasma and gas are responsible for an extreme range of sizes and shapes of the global heliosphere throughout its history. This, in turn, has had dramatic consequence for the penetration interstellar dust and galactic cosmic rays that have affected several crucial aspects of elemental and isotopic abundances, atmospheric evolution and conditions for habitability. Despite the importance for the heliosphere and other astrospheres, the interaction mechanisms at the heliospheric boundary could not be understood by the limited Voyager payloads and represent a new regime of space physics. At the same time, the lack of direct access to pristine interstellar material has prevented progress in understanding the physics of the interstellar clouds and galactic evolution. A new science frontier awaits heliophysics by exploring the outer heliosphere, its boundary and beyond out to 400-1000 AU, a region now being made accessible within realistic mission design lifetimes by the increasing availability of large launch vehicles.

Authorship

Brandt, P. C. + 88 co-authors

Contact

Pontus C. Brandt (pontus.brandt@jhuapl.edu)

Title

Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Description

NASA’s heliospheric division studies “the Sun, the heliosphere, and Earth’s magnetosphere and... universal plasma phenomena”. We will argue that Jupiter's radiation belts, magnetosphere, and near-space environment should be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s magnetosphere covers all universal processes called out in the 2013 Decadal. Space plasma physics at planetary systems is much more relevant to the defined focus of NASA’s Heliophysics division than for the core sciences of the planetary division. Jupiter’s giant magnetosphere hosts a wealth of particle species and charges subject to processes that can be studied with less ambiguity relative to Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to investigate a wide range of space plasma processes. Its magnetosphere continuously accelerates particles to higher energies than what is even reached during extreme space weather events. Jupiter covers such an immense parameter range in particle energies, magnetic field, and waves that it can bridge the in-situ study of magnetospheres and the remote observation of extrasolar systems like supernova remnants.

Authorship

everybody who is interested

Contact

Peter Kollmann (Peter.Kollmann@jhuapl.edu)

Title

The Case for Broadening the Scope of Heliophysics

Description

Moving forward, hopefully starting with the next Decadal Survey and certainly by 2050, the solar and space physics community should focus emphasis on the general and fundamental importance and excitement of its science with a new mindset: Heliophysics is a fundamental science discipline that is interwoven with planetary science, astrophysics, geoscience, and laboratory plasma physics. It is the study of the very nature of plasmas throughout space, originating with our own Sun and heliosphere and extending to planetary atmospheres and magnetospheres, stellar atmospheres and astrospheres, interstellar space, and more exotic magnetized plasma regimes like pulsars, black holes, and supernovae.

Authorship

Ian Cohen, Matina Gkioulidou, Drew Turner, Romina Nikoukar, Joe Westlake (JHU/APL); Aleida Higginson (NASA/GSFC); Ryan McGranaghan (ASTRA); Gordon Emslie (WKU); Dan Baker (LASP); and Harlan Spence (UNH)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

Title

The potential of the Interstellar Probe for measuring in-situ interstellar neutrals

Description

A near-term Interstellar Probe would enable in-situ measurements of the interstellar medium all the way from the Earth to the heliosheath and beyond the reaches of the heliopause. These revolutionary measurements would reveal how the interstellar medium is filtrated and deflected by our heliosphere and the chemical and isotopical composition of the unperturbed interstellar medium itself.

Authorship

Andre Galli, Seth Redfield, Elena Provornikova, Harald Kucharek, Paweł Swaczyna, Justyna M. Sokół, Marzena A. Kubiak, Ben L. Alterman

Contact

Andre Galli (andre.galli@space.unibe.ch)

Title

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium

Description

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium Jeffrey L. Linsky1 and Seth Redfield2 1JILA, University of Colorado and NIST, Boulder, CO 80309-0440, USA 2Astronomy Department and Van Vleck Observatory, Wesleyan University, Middletown, CT 06459-0123, USA ABSTRACT Our understanding of the outer heliosphere is becoming clearer from direct measurements by the Voyager spacecraft and theoretical models, but what lies beyond the heliopause in the Very Local Interstellar Medium (VLISM) and beyond in the pristine Local Interstellar Medium (LISM) is a new frontier of heliospheric research. This white paper for the Heliophysics 2050 Workshop describes critical questions concerning the plasma and magnetic field and physical processes in the VLISM and LISM. 1. THE PRESENT PICTURE The heliosphere is the interface between our solar system and the rest of the galaxy. Measurements using both heliospheric and astronomical techniques are required to fully understand the physical interactions and morphology of this interface. Measurements from both perspectives are needed to apply out knowledge of the heliosphere to analogous structures around other nearby stars, many of which host habitable planets, and to evaluate how the heliosphere has evolved and influenced the habitability of solar system planets. The Voyagers passed the termnation shock (TS) at 94 AU (V1) and 84 AU (V2) and traversed the heliopause (HP) at 122 AU (V1) and 119 AU (V2). Beyond the HP, interstellar plasma is modified by the inclusion of pickup ions and anomalous cosmic rays created in the TS and heliosheath that leak into the VLISM through the HP. This region was called the Very Local Interstellar Medium (VLISM) by Zank (2015). Inside the VLISM, charge exchange reactions between inflowing hydrogen atoms and energetic solar wind protons create the “hydrogen wall” (HW) where hydrogen atoms are piled up (increased density), heated, and slowed down relative to the inflow speed of neutral hydrogen from the pristine LISM. Hydrogen wall absorption in the Lyman-α line measures solar or stellar mass-loss rates. Figure 1 shows a heliosphere model where the HW is seen as a neutral hydrogen density enhancement outside of the HP. In models by Zank et al. (2013), the maximum density in the HW occurs near 300 AU and extends outward to 400–600 AU depending on the local magnetic field strength. The only direct measurements of the inflowing VLISM gas are the neutral helium atoms that penetrate the heliosphere relatively unscathed by charge exchange reactions and neutral hydrogen atoms modified by charge exchange reactions and identified by backscattered Lyman-α radiation. Beyond the VLISM, perhaps 500–700 AU from the Sun, is the pristine Local Interstellar Medium (LISM) for which there are no direct measurements. We have only a crude understanding of the LISM based only on theory and remote measurements. 2. VLISM SCIENCE QUESTIONS Models of the HWand VLISM computed with a MHD plasma – kinetic hydrogen code by 2 Figure 1. The heliosphere model computed by Richardson & Stone (2009). The top half shows the temperature structure. The bottom half shows the neutral hydrogen density. The HW is between 200 and 250 AU in the upwind direction. Zank et al. (2013) show that the VLISM magnetic field plays a critical role in determining (i) whether the decelerating LISM plasma has a bow shock or a bow wave, (ii) the amount of heating in the VLISM, and (iii) the neutral H column density density in the HW. Absorption in the Lyman-α line is best described by their model with a VLISM magnetic field of 3 μG, the same value inferred from observations of the IBEX ribbon (Zirnstein et al 2016). Other processes, known and unknown, shape the VLISM plasma. For example, pickup ions produced near the TS and accelerated ions (anomalous cosmic rays) dominate the heliosheath pressure. Gloeckler & Fisk (2016) estimate the total pressure just beyond the HP by balancing the total pressure on both sides of the HP. They estimate that the total gas pressure pressure just beyond the HP as P(tot)/k = 25, 855 Kcm−3, whereas the total gas and magnetic pressure in the inner LISM is only 5,565 Kcm−3 (Frisch et al. 2011), a factor of 4–5 times smaller. To balance the total pressure, the magnetic field just outside of the HP should be about 8 μG, which is far larger than measured by V1 and somewhat larger than measured by V2. On this basis V1 and V2 have not yet have crossed the HP. Direct measurements of the thermal and nonthermal plasma and magnetic fields are needed to understand the VLISM and test the models. In particular, we need to know how far out solar energetic neutrals and ions extend and the length scales for charge exchange and thermalization processes in order to determine where the VLISM ends and the pristine LISM begins. 3. LISM SCIENCE QUESTIONS Absorption line measurements of interstellar gas in the sightlines to nearby stars are the primary data set used to construct models of the LISM. Analysis of HST ultraviolet spectra yield line of sight average measurements of elemental abundances, ionization states, and velocity structure between the Sun and stars. Redfield & Linsky identified 15 clouds in the LISM by common velocity vectors towards stars. Each of these clouds has a mean temperature of 5,000–10,000 K. Linsky et al. (2019) showed that four clouds (see Figure 2) are very near the outer heliosphere. Local Interstellar Cloud (LIC) absorption covers less than half the sky, indicating that the gas entering the VLISM and heliosphere may be at the edge LIC with somewhat different properties than in the LIC center. The neutral hydrogen density in the LIC had been estimated to be 0.195 cm−3 (Slavin & Frisch 2008) or about 0.12 cm−3 on the basis V2 and Cassini/INCA measurements (Dialynas et al. 2019). However, these are rough estimates of the mean hydrogen density in only one of the LISM clouds. Direct measurements of neutrals, electrons, and ions are needed to study the properties of the LISM. 3 Figure 2. Morphologies of the four partially ionized LISM clouds that are near the outer heliosphere: the LIC (red), which lies in front of ǫ Eri (3.2 pc), the G cloud (brown), which lies in front of α Cen (1.32 pc), the Blue cloud (dark blue), which lies in front of Sirius (2.64 pc), and the Aql cloud (green), which lies in front of 61 Cyg (3.5 pc). The plot is in Galactic coordinates with the Galactic Center direction in the center. The LIC upwind direction is indicated by the circled-cross symbol near l = 15◦ and b = +20◦, and the upwind directions of the other clouds have similar marks. The heliosphere is now exiting the LIC in the direction of the neighboring G cloud. Upper limits on the amount of interstellar Mg II absorption in this direction predict that the heliosphere will leave the LIC in less than 1900 years and perhaps this year. This would be a major event. Will the heliosphere directly enter the G cloud or a photoionized boundary layer with little neutral hydrogen? The size of the heliosphere and the composition of its plasma will change in either scenario. The EUVE satellite discovered that the star ǫ CMa (ecliptic coordinates λ = 111◦, β = −51◦ and distance 124 pc) is the the brightest source of extreme-UV radiation. EUV photons from ǫ CMa produce a very large photoionized region (called a Str¨omgren sphere) that surrounds the LISM warm clouds and the partially ionized Str¨omgren shells on the outer regions of the LISM clouds. EUV radiation from ǫ CMa photoionizes neutral hydrogen producing very low neutral hydrogen column density in this direction called the “hydrogen hole”. The role of photoionization must be tested. Magnetic fields will be important in shaping the morphology of clouds if the magnetic pressure exceeds the gas pressure, which would occur if BLISM > 3μG. Stronger magnetic fields just beyond the HP observed by V2 (Dialynas et al.(2019) suggest that magnetic fields may dominate the pressure in the LISM clouds. The very low density plasma in the LISM may include non-thermal particles that dominate the total pressure. Supernovae in the nearby Scorpio-Centaurus Association have occured as recently as a few million years ago and their shock waves produced high ionization in the LISM that may still be recombining. The ram pressure of supernovae shocks can dominate other sources of pressure in the simulations of Berghofer & Breitschwerdt (2002). Recent models of the velocity distribution of plasma in the outer heliosphere include non-thermal components (Swaczya et al. 2019). Future analysis of LISM absorption line profiles should test for high velocity tails using kappa distributions. The relative importance of these and potentially other sources of ionization and morphology in the LISM need to be understood. Direct measurements of thermal and non-thermal plasma and magnetic fields can accomplish this. References: Berghofer & Breitschwerdt (2002) Astron. Astrphys. 390, 299. Dialynas et al. (2019) Geophys. Res. Let. 46, 7911. Frisch et al. (2011) ARAA 49, 237. Gloeckler & Fisk (2016) ApJ 833, 290. Linsky et al. (2019) ApJ 886, 41. Redfield & Linsky (2008) ApJ 673, 283. Richardson & Stone (2009) Space Sci. Rev 143, 7. Swaczyna et al. (2019) ApJ 871, 254. Zank et al. (2013) ApJ 763, 20. Zirnstein et al. (2016) ApJ 818, L18.

Authorship

Jeffrey L. Linsky and Seth Redfield

Contact

Jeffrey Linsky (jlinsky@jila.colorado.edu)

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Fundamental physics (e.g., shocks, reconnection)

Title

Description

Authorship

Contact

Title

Expanding the Realm of Solar & Space Physics: Exploration of the Outer Heliosphere and Local Interstellar Medium

Description

During its evolutionary journey through the galaxy, the Sun and its protective heliosphere have encountered widely different environments that have all helped form the system we live in, and soon our star will enter a completely new region of interstellar space. The orders-of-magnitude varying properties of interstellar plasma and gas are responsible for an extreme range of sizes and shapes of the global heliosphere throughout its history. This, in turn, has had dramatic consequence for the penetration interstellar dust and galactic cosmic rays that have affected several crucial aspects of elemental and isotopic abundances, atmospheric evolution and conditions for habitability. Despite the importance for the heliosphere and other astrospheres, the interaction mechanisms at the heliospheric boundary could not be understood by the limited Voyager payloads and represent a new regime of space physics. At the same time, the lack of direct access to pristine interstellar material has prevented progress in understanding the physics of the interstellar clouds and galactic evolution. A new science frontier awaits heliophysics by exploring the outer heliosphere, its boundary and beyond out to 400-1000 AU, a region now being made accessible within realistic mission design lifetimes by the increasing availability of large launch vehicles.

Authorship

Brandt, P. C. + 88 co-authors

Contact

Pontus C. Brandt (pontus.brandt@jhuapl.edu)

Title

Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Description

NASA’s heliospheric division studies “the Sun, the heliosphere, and Earth’s magnetosphere and... universal plasma phenomena”. We will argue that Jupiter's radiation belts, magnetosphere, and near-space environment should be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s magnetosphere covers all universal processes called out in the 2013 Decadal. Space plasma physics at planetary systems is much more relevant to the defined focus of NASA’s Heliophysics division than for the core sciences of the planetary division. Jupiter’s giant magnetosphere hosts a wealth of particle species and charges subject to processes that can be studied with less ambiguity relative to Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to investigate a wide range of space plasma processes. Its magnetosphere continuously accelerates particles to higher energies than what is even reached during extreme space weather events. Jupiter covers such an immense parameter range in particle energies, magnetic field, and waves that it can bridge the in-situ study of magnetospheres and the remote observation of extrasolar systems like supernova remnants.

Authorship

everybody who is interested

Contact

Peter Kollmann (Peter.Kollmann@jhuapl.edu)

Title

The role of kappa distributions in Space Thermodynamics

Description

Classical collisional particle systems residing in thermal equilibrium have their particle velocity/energy distribution function stabilized into a Maxwell-Boltzmann distribution. On the contrary, space plasmas are collisionless particle systems residing in stationary states characterized by a non-Maxwellian behavior, typically described by kappa distributions. These distributions have become increasingly widespread across the physics of space plasma processes, describing particles in the heliosphere, from the solar wind and planetary magnetospheres to the heliosheath and beyond, the interstellar and intergalactic plasmas. A breakthrough in the field came with the connection of kappa distributions with statistical mechanics and thermodynamics. In particular, (i) maximize the entropy of nonextensive statistical mechanics under the constraints of canonical ensemble, (ii) characterize particle systems exchanging heat with each other eventually stabilized at a non-classical version of thermal equilibrium, and (iii) constitute the unique description of particle energies consistent with polytropic behavior.

Authorship

George Livadiotis

Contact

George Livadiotis (glivadiotis@swri.edu)

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Space Weather


Space weather basic and applied research

Title

Description

Authorship

Contact

Title

Accessibility and inclusive development for solar flares radiation exposure

Description

The solar flares radiation exposure causes impacts and effects on the health of the human individuals who are exposed to this solar energy. This leads to the creation of new innovations built in the subject areas of Accessibility and inclusive development in the platform channels of information and communication technologies and artificial intelligence and robotics. Also this Innovative ideology is extracted to a variety of different sectors, namely, the food systems and the smart agriculture. An innovative ideology product solution is provided in the website URL and link which is mentioned here below:- https://solarflaresandthefoodcrops.webnode.in

Authorship

Ashwini Sathnur, NASA SBAG working group Member

Contact

Ashwini Sathnur (ashwiniashis@yahoo.com)

Title

The role of kappa distributions in Space Thermodynamics

Description

Classical collisional particle systems residing in thermal equilibrium have their particle velocity/energy distribution function stabilized into a Maxwell-Boltzmann distribution. On the contrary, space plasmas are collisionless particle systems residing in stationary states characterized by a non-Maxwellian behavior, typically described by kappa distributions. These distributions have become increasingly widespread across the physics of space plasma processes, describing particles in the heliosphere, from the solar wind and planetary magnetospheres to the heliosheath and beyond, the interstellar and intergalactic plasmas. A breakthrough in the field came with the connection of kappa distributions with statistical mechanics and thermodynamics. In particular, (i) maximize the entropy of nonextensive statistical mechanics under the constraints of canonical ensemble, (ii) characterize particle systems exchanging heat with each other eventually stabilized at a non-classical version of thermal equilibrium, and (iii) constitute the unique description of particle energies consistent with polytropic behavior.

Authorship

George Livadiotis

Contact

George Livadiotis (glivadiotis@swri.edu)

Title

Towards a Better Understanding of the Causes and Consequences of Geomagnetic Perturbations in 2050

Description

Disturbances in the magnetic field at the Earth’s surface are at the center of Heliophysics and Space Weather research: remote sensing magnetosphere-ionosphere current systems, construction of geomagnetic indices used for space weather forecasts and model validation, monitoring of geoelectric fields and related Geomagnetically Induced Currents (GIC). The purpose of this white paper is to highlight future research, instrumentation, and community/inter-agency efforts that are needed to improve our understanding of the causes and consequences of these perturbations.

Authorship

Michael Hartinger +10 co-authors

Contact

Michael Hartinger (mhartinger@spacescience.org)

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Space weather operations

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Description

Authorship

Contact

Title

 

Description

 

Authorship

 

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Enabling Operations


Observatories (e.g., space-based platforms, ground-based observatories, ground-to-spacecraft communication, systems and subsystems)

Title

Description

Authorship

Contact

Title

Towards a Better Understanding of the Causes and Consequences of Geomagnetic Perturbations in 2050

Description

Disturbances in the magnetic field at the Earth’s surface are at the center of Heliophysics and Space Weather research: remote sensing magnetosphere-ionosphere current systems, construction of geomagnetic indices used for space weather forecasts and model validation, monitoring of geoelectric fields and related Geomagnetically Induced Currents (GIC). The purpose of this white paper is to highlight future research, instrumentation, and community/inter-agency efforts that are needed to improve our understanding of the causes and consequences of these perturbations.

Authorship

Michael Hartinger +10 co-authors

Contact

Michael Hartinger (mhartinger@spacescience.org)

Title

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium

Description

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium Jeffrey L. Linsky1 and Seth Redfield2 1JILA, University of Colorado and NIST, Boulder, CO 80309-0440, USA 2Astronomy Department and Van Vleck Observatory, Wesleyan University, Middletown, CT 06459-0123, USA ABSTRACT Our understanding of the outer heliosphere is becoming clearer from direct measurements by the Voyager spacecraft and theoretical models, but what lies beyond the heliopause in the Very Local Interstellar Medium (VLISM) and beyond in the pristine Local Interstellar Medium (LISM) is a new frontier of heliospheric research. This white paper for the Heliophysics 2050 Workshop describes critical questions concerning the plasma and magnetic field and physical processes in the VLISM and LISM. 1. THE PRESENT PICTURE The heliosphere is the interface between our solar system and the rest of the galaxy. Measurements using both heliospheric and astronomical techniques are required to fully understand the physical interactions and morphology of this interface. Measurements from both perspectives are needed to apply out knowledge of the heliosphere to analogous structures around other nearby stars, many of which host habitable planets, and to evaluate how the heliosphere has evolved and influenced the habitability of solar system planets. The Voyagers passed the termnation shock (TS) at 94 AU (V1) and 84 AU (V2) and traversed the heliopause (HP) at 122 AU (V1) and 119 AU (V2). Beyond the HP, interstellar plasma is modified by the inclusion of pickup ions and anomalous cosmic rays created in the TS and heliosheath that leak into the VLISM through the HP. This region was called the Very Local Interstellar Medium (VLISM) by Zank (2015). Inside the VLISM, charge exchange reactions between inflowing hydrogen atoms and energetic solar wind protons create the “hydrogen wall” (HW) where hydrogen atoms are piled up (increased density), heated, and slowed down relative to the inflow speed of neutral hydrogen from the pristine LISM. Hydrogen wall absorption in the Lyman-α line measures solar or stellar mass-loss rates. Figure 1 shows a heliosphere model where the HW is seen as a neutral hydrogen density enhancement outside of the HP. In models by Zank et al. (2013), the maximum density in the HW occurs near 300 AU and extends outward to 400–600 AU depending on the local magnetic field strength. The only direct measurements of the inflowing VLISM gas are the neutral helium atoms that penetrate the heliosphere relatively unscathed by charge exchange reactions and neutral hydrogen atoms modified by charge exchange reactions and identified by backscattered Lyman-α radiation. Beyond the VLISM, perhaps 500–700 AU from the Sun, is the pristine Local Interstellar Medium (LISM) for which there are no direct measurements. We have only a crude understanding of the LISM based only on theory and remote measurements. 2. VLISM SCIENCE QUESTIONS Models of the HWand VLISM computed with a MHD plasma – kinetic hydrogen code by 2 Figure 1. The heliosphere model computed by Richardson & Stone (2009). The top half shows the temperature structure. The bottom half shows the neutral hydrogen density. The HW is between 200 and 250 AU in the upwind direction. Zank et al. (2013) show that the VLISM magnetic field plays a critical role in determining (i) whether the decelerating LISM plasma has a bow shock or a bow wave, (ii) the amount of heating in the VLISM, and (iii) the neutral H column density density in the HW. Absorption in the Lyman-α line is best described by their model with a VLISM magnetic field of 3 μG, the same value inferred from observations of the IBEX ribbon (Zirnstein et al 2016). Other processes, known and unknown, shape the VLISM plasma. For example, pickup ions produced near the TS and accelerated ions (anomalous cosmic rays) dominate the heliosheath pressure. Gloeckler & Fisk (2016) estimate the total pressure just beyond the HP by balancing the total pressure on both sides of the HP. They estimate that the total gas pressure pressure just beyond the HP as P(tot)/k = 25, 855 Kcm−3, whereas the total gas and magnetic pressure in the inner LISM is only 5,565 Kcm−3 (Frisch et al. 2011), a factor of 4–5 times smaller. To balance the total pressure, the magnetic field just outside of the HP should be about 8 μG, which is far larger than measured by V1 and somewhat larger than measured by V2. On this basis V1 and V2 have not yet have crossed the HP. Direct measurements of the thermal and nonthermal plasma and magnetic fields are needed to understand the VLISM and test the models. In particular, we need to know how far out solar energetic neutrals and ions extend and the length scales for charge exchange and thermalization processes in order to determine where the VLISM ends and the pristine LISM begins. 3. LISM SCIENCE QUESTIONS Absorption line measurements of interstellar gas in the sightlines to nearby stars are the primary data set used to construct models of the LISM. Analysis of HST ultraviolet spectra yield line of sight average measurements of elemental abundances, ionization states, and velocity structure between the Sun and stars. Redfield & Linsky identified 15 clouds in the LISM by common velocity vectors towards stars. Each of these clouds has a mean temperature of 5,000–10,000 K. Linsky et al. (2019) showed that four clouds (see Figure 2) are very near the outer heliosphere. Local Interstellar Cloud (LIC) absorption covers less than half the sky, indicating that the gas entering the VLISM and heliosphere may be at the edge LIC with somewhat different properties than in the LIC center. The neutral hydrogen density in the LIC had been estimated to be 0.195 cm−3 (Slavin & Frisch 2008) or about 0.12 cm−3 on the basis V2 and Cassini/INCA measurements (Dialynas et al. 2019). However, these are rough estimates of the mean hydrogen density in only one of the LISM clouds. Direct measurements of neutrals, electrons, and ions are needed to study the properties of the LISM. 3 Figure 2. Morphologies of the four partially ionized LISM clouds that are near the outer heliosphere: the LIC (red), which lies in front of ǫ Eri (3.2 pc), the G cloud (brown), which lies in front of α Cen (1.32 pc), the Blue cloud (dark blue), which lies in front of Sirius (2.64 pc), and the Aql cloud (green), which lies in front of 61 Cyg (3.5 pc). The plot is in Galactic coordinates with the Galactic Center direction in the center. The LIC upwind direction is indicated by the circled-cross symbol near l = 15◦ and b = +20◦, and the upwind directions of the other clouds have similar marks. The heliosphere is now exiting the LIC in the direction of the neighboring G cloud. Upper limits on the amount of interstellar Mg II absorption in this direction predict that the heliosphere will leave the LIC in less than 1900 years and perhaps this year. This would be a major event. Will the heliosphere directly enter the G cloud or a photoionized boundary layer with little neutral hydrogen? The size of the heliosphere and the composition of its plasma will change in either scenario. The EUVE satellite discovered that the star ǫ CMa (ecliptic coordinates λ = 111◦, β = −51◦ and distance 124 pc) is the the brightest source of extreme-UV radiation. EUV photons from ǫ CMa produce a very large photoionized region (called a Str¨omgren sphere) that surrounds the LISM warm clouds and the partially ionized Str¨omgren shells on the outer regions of the LISM clouds. EUV radiation from ǫ CMa photoionizes neutral hydrogen producing very low neutral hydrogen column density in this direction called the “hydrogen hole”. The role of photoionization must be tested. Magnetic fields will be important in shaping the morphology of clouds if the magnetic pressure exceeds the gas pressure, which would occur if BLISM > 3μG. Stronger magnetic fields just beyond the HP observed by V2 (Dialynas et al.(2019) suggest that magnetic fields may dominate the pressure in the LISM clouds. The very low density plasma in the LISM may include non-thermal particles that dominate the total pressure. Supernovae in the nearby Scorpio-Centaurus Association have occured as recently as a few million years ago and their shock waves produced high ionization in the LISM that may still be recombining. The ram pressure of supernovae shocks can dominate other sources of pressure in the simulations of Berghofer & Breitschwerdt (2002). Recent models of the velocity distribution of plasma in the outer heliosphere include non-thermal components (Swaczya et al. 2019). Future analysis of LISM absorption line profiles should test for high velocity tails using kappa distributions. The relative importance of these and potentially other sources of ionization and morphology in the LISM need to be understood. Direct measurements of thermal and non-thermal plasma and magnetic fields can accomplish this. References: Berghofer & Breitschwerdt (2002) Astron. Astrphys. 390, 299. Dialynas et al. (2019) Geophys. Res. Let. 46, 7911. Frisch et al. (2011) ARAA 49, 237. Gloeckler & Fisk (2016) ApJ 833, 290. Linsky et al. (2019) ApJ 886, 41. Redfield & Linsky (2008) ApJ 673, 283. Richardson & Stone (2009) Space Sci. Rev 143, 7. Swaczyna et al. (2019) ApJ 871, 254. Zank et al. (2013) ApJ 763, 20. Zirnstein et al. (2016) ApJ 818, L18.

Authorship

Jeffrey L. Linsky and Seth Redfield

Contact

Jeffrey Linsky (jlinsky@jila.colorado.edu)

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Cyberinfrastructure (e.g., data archives, computational capabilities)

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Title

Accessibility and inclusive development for solar flares radiation exposure

Description

The solar flares radiation exposure causes impacts and effects on the health of the human individuals who are exposed to this solar energy. This leads to the creation of new innovations built in the subject areas of Accessibility and inclusive development in the platform channels of information and communication technologies and artificial intelligence and robotics. Also this Innovative ideology is extracted to a variety of different sectors, namely, the food systems and the smart agriculture. An innovative ideology product solution is provided in the website URL and link which is mentioned here below:- https://solarflaresandthefoodcrops.webnode.in

Authorship

Ashwini Sathnur, NASA SBAG working group Member

Contact

Ashwini Sathnur (ashwiniashis@yahoo.com)

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Supporting capabilities (e.g., laboratory measurements, theoretical and computational models, analysis tools)

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Description

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Title

Accessibility and inclusive development for solar flares radiation exposure

Description

The solar flares radiation exposure causes impacts and effects on the health of the human individuals who are exposed to this solar energy. This leads to the creation of new innovations built in the subject areas of Accessibility and inclusive development in the platform channels of information and communication technologies and artificial intelligence and robotics. Also this Innovative ideology is extracted to a variety of different sectors, namely, the food systems and the smart agriculture. An innovative ideology product solution is provided in the website URL and link which is mentioned here below:- https://solarflaresandthefoodcrops.webnode.in

Authorship

Ashwini Sathnur, NASA SBAG working group Member

Contact

Ashwini Sathnur (ashwiniashis@yahoo.com)

Title

Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Description

NASA’s heliospheric division studies “the Sun, the heliosphere, and Earth’s magnetosphere and... universal plasma phenomena”. We will argue that Jupiter's radiation belts, magnetosphere, and near-space environment should be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s magnetosphere covers all universal processes called out in the 2013 Decadal. Space plasma physics at planetary systems is much more relevant to the defined focus of NASA’s Heliophysics division than for the core sciences of the planetary division. Jupiter’s giant magnetosphere hosts a wealth of particle species and charges subject to processes that can be studied with less ambiguity relative to Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to investigate a wide range of space plasma processes. Its magnetosphere continuously accelerates particles to higher energies than what is even reached during extreme space weather events. Jupiter covers such an immense parameter range in particle energies, magnetic field, and waves that it can bridge the in-situ study of magnetospheres and the remote observation of extrasolar systems like supernova remnants.

Authorship

everybody who is interested

Contact

Peter Kollmann (Peter.Kollmann@jhuapl.edu)

Title

The Case for Broadening the Scope of Heliophysics

Description

Moving forward, hopefully starting with the next Decadal Survey and certainly by 2050, the solar and space physics community should focus emphasis on the general and fundamental importance and excitement of its science with a new mindset: Heliophysics is a fundamental science discipline that is interwoven with planetary science, astrophysics, geoscience, and laboratory plasma physics. It is the study of the very nature of plasmas throughout space, originating with our own Sun and heliosphere and extending to planetary atmospheres and magnetospheres, stellar atmospheres and astrospheres, interstellar space, and more exotic magnetized plasma regimes like pulsars, black holes, and supernovae.

Authorship

Ian Cohen, Matina Gkioulidou, Drew Turner, Romina Nikoukar, Joe Westlake (JHU/APL); Aleida Higginson (NASA/GSFC); Ryan McGranaghan (ASTRA); Gordon Emslie (WKU); Dan Baker (LASP); and Harlan Spence (UNH)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

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Additional Topics


Agency programmatic items (e.g., programs, partnerships, collaborations, decision rules/prioritizations)

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Title

Jupiter’s radiation belts as a target for NASA’s Heliophysics Division

Description

NASA’s heliospheric division studies “the Sun, the heliosphere, and Earth’s magnetosphere and... universal plasma phenomena”. We will argue that Jupiter's radiation belts, magnetosphere, and near-space environment should be considered as relevant targets for NASA’s Heliophysics missions. Jupiter’s magnetosphere covers all universal processes called out in the 2013 Decadal. Space plasma physics at planetary systems is much more relevant to the defined focus of NASA’s Heliophysics division than for the core sciences of the planetary division. Jupiter’s giant magnetosphere hosts a wealth of particle species and charges subject to processes that can be studied with less ambiguity relative to Earth thanks to spatial unmixing. This makes Jupiter an ideal laboratory to investigate a wide range of space plasma processes. Its magnetosphere continuously accelerates particles to higher energies than what is even reached during extreme space weather events. Jupiter covers such an immense parameter range in particle energies, magnetic field, and waves that it can bridge the in-situ study of magnetospheres and the remote observation of extrasolar systems like supernova remnants.

Authorship

everybody who is interested

Contact

Peter Kollmann (Peter.Kollmann@jhuapl.edu)

Title

The Case for Broadening the Scope of Heliophysics

Description

Moving forward, hopefully starting with the next Decadal Survey and certainly by 2050, the solar and space physics community should focus emphasis on the general and fundamental importance and excitement of its science with a new mindset: Heliophysics is a fundamental science discipline that is interwoven with planetary science, astrophysics, geoscience, and laboratory plasma physics. It is the study of the very nature of plasmas throughout space, originating with our own Sun and heliosphere and extending to planetary atmospheres and magnetospheres, stellar atmospheres and astrospheres, interstellar space, and more exotic magnetized plasma regimes like pulsars, black holes, and supernovae.

Authorship

Ian Cohen, Matina Gkioulidou, Drew Turner, Romina Nikoukar, Joe Westlake (JHU/APL); Aleida Higginson (NASA/GSFC); Ryan McGranaghan (ASTRA); Gordon Emslie (WKU); Dan Baker (LASP); and Harlan Spence (UNH)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

Title

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium

Description

What Lies Outside of the Heliopause: Connecting the Outer Heliosphere with the Interstellar Medium Jeffrey L. Linsky1 and Seth Redfield2 1JILA, University of Colorado and NIST, Boulder, CO 80309-0440, USA 2Astronomy Department and Van Vleck Observatory, Wesleyan University, Middletown, CT 06459-0123, USA ABSTRACT Our understanding of the outer heliosphere is becoming clearer from direct measurements by the Voyager spacecraft and theoretical models, but what lies beyond the heliopause in the Very Local Interstellar Medium (VLISM) and beyond in the pristine Local Interstellar Medium (LISM) is a new frontier of heliospheric research. This white paper for the Heliophysics 2050 Workshop describes critical questions concerning the plasma and magnetic field and physical processes in the VLISM and LISM. 1. THE PRESENT PICTURE The heliosphere is the interface between our solar system and the rest of the galaxy. Measurements using both heliospheric and astronomical techniques are required to fully understand the physical interactions and morphology of this interface. Measurements from both perspectives are needed to apply out knowledge of the heliosphere to analogous structures around other nearby stars, many of which host habitable planets, and to evaluate how the heliosphere has evolved and influenced the habitability of solar system planets. The Voyagers passed the termnation shock (TS) at 94 AU (V1) and 84 AU (V2) and traversed the heliopause (HP) at 122 AU (V1) and 119 AU (V2). Beyond the HP, interstellar plasma is modified by the inclusion of pickup ions and anomalous cosmic rays created in the TS and heliosheath that leak into the VLISM through the HP. This region was called the Very Local Interstellar Medium (VLISM) by Zank (2015). Inside the VLISM, charge exchange reactions between inflowing hydrogen atoms and energetic solar wind protons create the “hydrogen wall” (HW) where hydrogen atoms are piled up (increased density), heated, and slowed down relative to the inflow speed of neutral hydrogen from the pristine LISM. Hydrogen wall absorption in the Lyman-α line measures solar or stellar mass-loss rates. Figure 1 shows a heliosphere model where the HW is seen as a neutral hydrogen density enhancement outside of the HP. In models by Zank et al. (2013), the maximum density in the HW occurs near 300 AU and extends outward to 400–600 AU depending on the local magnetic field strength. The only direct measurements of the inflowing VLISM gas are the neutral helium atoms that penetrate the heliosphere relatively unscathed by charge exchange reactions and neutral hydrogen atoms modified by charge exchange reactions and identified by backscattered Lyman-α radiation. Beyond the VLISM, perhaps 500–700 AU from the Sun, is the pristine Local Interstellar Medium (LISM) for which there are no direct measurements. We have only a crude understanding of the LISM based only on theory and remote measurements. 2. VLISM SCIENCE QUESTIONS Models of the HWand VLISM computed with a MHD plasma – kinetic hydrogen code by 2 Figure 1. The heliosphere model computed by Richardson & Stone (2009). The top half shows the temperature structure. The bottom half shows the neutral hydrogen density. The HW is between 200 and 250 AU in the upwind direction. Zank et al. (2013) show that the VLISM magnetic field plays a critical role in determining (i) whether the decelerating LISM plasma has a bow shock or a bow wave, (ii) the amount of heating in the VLISM, and (iii) the neutral H column density density in the HW. Absorption in the Lyman-α line is best described by their model with a VLISM magnetic field of 3 μG, the same value inferred from observations of the IBEX ribbon (Zirnstein et al 2016). Other processes, known and unknown, shape the VLISM plasma. For example, pickup ions produced near the TS and accelerated ions (anomalous cosmic rays) dominate the heliosheath pressure. Gloeckler & Fisk (2016) estimate the total pressure just beyond the HP by balancing the total pressure on both sides of the HP. They estimate that the total gas pressure pressure just beyond the HP as P(tot)/k = 25, 855 Kcm−3, whereas the total gas and magnetic pressure in the inner LISM is only 5,565 Kcm−3 (Frisch et al. 2011), a factor of 4–5 times smaller. To balance the total pressure, the magnetic field just outside of the HP should be about 8 μG, which is far larger than measured by V1 and somewhat larger than measured by V2. On this basis V1 and V2 have not yet have crossed the HP. Direct measurements of the thermal and nonthermal plasma and magnetic fields are needed to understand the VLISM and test the models. In particular, we need to know how far out solar energetic neutrals and ions extend and the length scales for charge exchange and thermalization processes in order to determine where the VLISM ends and the pristine LISM begins. 3. LISM SCIENCE QUESTIONS Absorption line measurements of interstellar gas in the sightlines to nearby stars are the primary data set used to construct models of the LISM. Analysis of HST ultraviolet spectra yield line of sight average measurements of elemental abundances, ionization states, and velocity structure between the Sun and stars. Redfield & Linsky identified 15 clouds in the LISM by common velocity vectors towards stars. Each of these clouds has a mean temperature of 5,000–10,000 K. Linsky et al. (2019) showed that four clouds (see Figure 2) are very near the outer heliosphere. Local Interstellar Cloud (LIC) absorption covers less than half the sky, indicating that the gas entering the VLISM and heliosphere may be at the edge LIC with somewhat different properties than in the LIC center. The neutral hydrogen density in the LIC had been estimated to be 0.195 cm−3 (Slavin & Frisch 2008) or about 0.12 cm−3 on the basis V2 and Cassini/INCA measurements (Dialynas et al. 2019). However, these are rough estimates of the mean hydrogen density in only one of the LISM clouds. Direct measurements of neutrals, electrons, and ions are needed to study the properties of the LISM. 3 Figure 2. Morphologies of the four partially ionized LISM clouds that are near the outer heliosphere: the LIC (red), which lies in front of ǫ Eri (3.2 pc), the G cloud (brown), which lies in front of α Cen (1.32 pc), the Blue cloud (dark blue), which lies in front of Sirius (2.64 pc), and the Aql cloud (green), which lies in front of 61 Cyg (3.5 pc). The plot is in Galactic coordinates with the Galactic Center direction in the center. The LIC upwind direction is indicated by the circled-cross symbol near l = 15◦ and b = +20◦, and the upwind directions of the other clouds have similar marks. The heliosphere is now exiting the LIC in the direction of the neighboring G cloud. Upper limits on the amount of interstellar Mg II absorption in this direction predict that the heliosphere will leave the LIC in less than 1900 years and perhaps this year. This would be a major event. Will the heliosphere directly enter the G cloud or a photoionized boundary layer with little neutral hydrogen? The size of the heliosphere and the composition of its plasma will change in either scenario. The EUVE satellite discovered that the star ǫ CMa (ecliptic coordinates λ = 111◦, β = −51◦ and distance 124 pc) is the the brightest source of extreme-UV radiation. EUV photons from ǫ CMa produce a very large photoionized region (called a Str¨omgren sphere) that surrounds the LISM warm clouds and the partially ionized Str¨omgren shells on the outer regions of the LISM clouds. EUV radiation from ǫ CMa photoionizes neutral hydrogen producing very low neutral hydrogen column density in this direction called the “hydrogen hole”. The role of photoionization must be tested. Magnetic fields will be important in shaping the morphology of clouds if the magnetic pressure exceeds the gas pressure, which would occur if BLISM > 3μG. Stronger magnetic fields just beyond the HP observed by V2 (Dialynas et al.(2019) suggest that magnetic fields may dominate the pressure in the LISM clouds. The very low density plasma in the LISM may include non-thermal particles that dominate the total pressure. Supernovae in the nearby Scorpio-Centaurus Association have occured as recently as a few million years ago and their shock waves produced high ionization in the LISM that may still be recombining. The ram pressure of supernovae shocks can dominate other sources of pressure in the simulations of Berghofer & Breitschwerdt (2002). Recent models of the velocity distribution of plasma in the outer heliosphere include non-thermal components (Swaczya et al. 2019). Future analysis of LISM absorption line profiles should test for high velocity tails using kappa distributions. The relative importance of these and potentially other sources of ionization and morphology in the LISM need to be understood. Direct measurements of thermal and non-thermal plasma and magnetic fields can accomplish this. References: Berghofer & Breitschwerdt (2002) Astron. Astrphys. 390, 299. Dialynas et al. (2019) Geophys. Res. Let. 46, 7911. Frisch et al. (2011) ARAA 49, 237. Gloeckler & Fisk (2016) ApJ 833, 290. Linsky et al. (2019) ApJ 886, 41. Redfield & Linsky (2008) ApJ 673, 283. Richardson & Stone (2009) Space Sci. Rev 143, 7. Swaczyna et al. (2019) ApJ 871, 254. Zank et al. (2013) ApJ 763, 20. Zirnstein et al. (2016) ApJ 818, L18.

Authorship

Jeffrey L. Linsky and Seth Redfield

Contact

Jeffrey Linsky (jlinsky@jila.colorado.edu)

Title

Why and How to Increase Cross-Divisional Opportunities

Description

Robotic space exploration, especially to far reaches of the solar system, is by its very nature difficult and expensive. As such, it behooves the entire space science community to work collaboratively to maximize the scientific return of missions, regardless of the primary funding Division. In the future, NASA should offer increased support and more opportunities enabling cross-Divisional science.

Authorship

Ian Cohen, Abigail Rymer, Drew Turner, Matina Gkioulidou, George Clark, Peter Kollmann, Sarah Vines, Robert Allen, Joseph Westlake, Romina Nikoukar (JHU/APL)

Contact

Ian Cohen (Ian.Cohen@jhuapl.edu)

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State of the Profession (e.g., workforce development, workforce retention, research community health, work environment, DEAI/IDEA)

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Science engagement (e.g., education, outreach, communication)

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Accessibility and inclusive development for solar flares radiation exposure

Description

The solar flares radiation exposure causes impacts and effects on the health of the human individuals who are exposed to this solar energy. This leads to the creation of new innovations built in the subject areas of Accessibility and inclusive development in the platform channels of information and communication technologies and artificial intelligence and robotics. Also this Innovative ideology is extracted to a variety of different sectors, namely, the food systems and the smart agriculture. An innovative ideology product solution is provided in the website URL and link which is mentioned here below:- https://solarflaresandthefoodcrops.webnode.in

Authorship

Ashwini Sathnur, NASA SBAG working group Member

Contact

Ashwini Sathnur (ashwiniashis@yahoo.com)

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Title

Accessibility and inclusive development for solar flares radiation exposure

Description

The solar flares radiation exposure causes impacts and effects on the health of the human individuals who are exposed to this solar energy. This leads to the creation of new innovations built in the subject areas of Accessibility and inclusive development in the platform channels of information and communication technologies and artificial intelligence and robotics. Also this Innovative ideology is extracted to a variety of different sectors, namely, the food systems and the smart agriculture. An innovative ideology product solution is provided in the website URL and link which is mentioned here below:- https://solarflaresandthefoodcrops.webnode.in

Authorship

Ashwini Sathnur, NASA SBAG working group Member

Contact

Ashwini Sathnur (ashwiniashis@yahoo.com)

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