Venus Science and Technology Interview Series
- Elise Harrington
- Peter Gao
- Ravi Kopparapu
- Erika Kohler
- Giada Amey
- Kandis Lea Jessup
- Martin Airey
- Candace Gray
- Constantine Tsang
Elise Harrington
B.Sc Hons Candidate
Department of Earth Sciences
Simon Fraser University
Interview conducted by Lynnae Quick
What do you find most intriguing about the planet Venus?
What I find most interesting about Venus is how her geology is affected by climate. The extreme heat, pressure, and absence of water leads to the planet having extremely different tectonics than what is seen on Earth. Similarly, the atmospheric conditions may lead to unique mineralogical signatures characterizing the highland areas and lowland plains; a geochemical gradient we don't see on Earth's surface. The geological differences between Venus and Earth, as a result of surficial and atmospheric disparity, are fascinating.
Please provide a brief description of your current research and how it's linked to Venus science (if this is not obvious).
Venus' highland areas appear brighter than its lowlands in reflected radar (i.e., Magellan Synthetic Aperture Radar). As temperature is the dominant variable which changes with elevation, this transition is inferred to be a temperature dependent process. The specific cause(s) are currently unknown and controversial, but hypotheses have been put forward suggesting variations in chemical weathering or precipitation of radar-reflective minerals from the atmosphere (i.e. a 'heavy metal frost'), although the chemical compounds involved are not known. Without new data about Venus' highlands, it is important to re-examine old data in new ways to understand the chemical processes at Venus' surface. Our objective is to refine the relationship between radar signatures and elevation for Venus highlands at high spatial resolution, using stereo topography (600m footprint, from R. Herrick) in place of radar altimetry (8x12km footprint) and using SAR reflectance (75m footprint) in place of emissivity (15x23km footprint). Our results thus far confirm and refine the conclusions of earlier work on Ovda Regio (a near-equatorial highlands region) and emphasize significant differences between it and Maxwell Montes (the highest elevations on Venus, at high northern latitude). These differences suggest that the two highlands regions were subject to different processes (geological, chemical, or atmospheric), or are made of different rock types.
Anything else you'd like to add?
I'm actually about to start my B.Sc Honours thesis under Dr. Glyn William-Jones at Simon Fraser University, which will also be related to Venus in some way. We haven't quite determined the topic, yet, but will likely be either looking for pyroclastic flows around some of Venus' volcanoes, or performing some flow modeling of the canali in the lowland plains.
Peter Gao
California Institute of Technology
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Interview conducted by Lynnae Quick
What do you find most intriguing about the planet Venus?
I think by far the most intriguing thing about Venus is how similar to Earth it could've been, and how far it has diverged since the dawn of the Solar System. Here is a planet that has almost the same radius and mass as Earth - so presumably the same composition - and yet its surface, atmosphere, and even rotation are vastly different. What caused this divergence? And in fact, was there a divergence, or was Venus somehow fundamentally different from Earth in its inception? If the divergence is real and ancient Venus was similar to ancient Earth, then the series of events that led to such striking differences should be heavily investigated to quantify how sensitive a terrestrial planet is to becoming a Venus vs. becoming an Earth, which is crucial as we enter the age of the "potentially habitable" terrestrial exoplanet.
Furthermore, if the differences between Venus and Earth are purely caused by the increased stellar flux, then this suggests a significant coupling between insolation, atmospheric processes, surface processes, and interior evolution. As such, Venus provides a perfect laboratory for probing the interactivity between different parts of a planet, especially when compared to the same processes occurring on Earth.
Please provide a brief description of your current research and how it's linked to Venus science (if this is not obvious).
My focus is mainly on the sulfuric acid clouds of Venus, which envelop the entire planet, and thus acts as a major factor in the dynamical, chemical, and radiative processes of the Venus atmosphere. I led a paper published in 2014 that tackled the time-variability of the coupled cloud deck-upper haze system using a microphysical cloud model, and found that transient upwelling events, possibly associated with local convective instability, led to the variability in the upper haze that had time scales of Earth days. I was also second author on a paper that extended our cloud model to many other latitudes, as well as one that investigated variability in the water and sulfur dioxide abundance in the Venus mesosphere. I am now working on adding sulfur microphysics to my cloud model in the hopes of shedding light on the Venus UV absorber mystery.
Please provide a webpage link to your research.
My research website can be found here: http://web.gps.caltech.edu/~pgao/.
Anything else you'd like to add?
The Universe gave us two planets right next to each other that are at once both extremely similar and extremely different: Let's not waste this opportunity.
Ravi Kopparapu
Assistant Research Scientist
NASA Goddard Space Flight Center
Visit Ravi's Research page
Interview conducted by Lynnae Quick
What do you find most intriguing about the planet Venus?
Its closeness in size and mass to our Earth. That it could have been possibly another habitable planet within our Solar system, if Mars and Venus swapped their locations! With it's present location, it could be considered to be at the limit where planetary habitability can be constrained. And it provides a great opportunity as a laboratory for studying 'runaway' greenhouse atmospheres, which is pretty important for future Earth (and exoplanet) habitability.
Please provide a brief description of your current research and how it's linked to Venus science (if this is not obvious).
My research work is to study the habitability limits of rocky planets around different stars from the perspective of atmospheric physics and astronomy. To that end, I use climate models (both 1-dimensional and 3-dimensional) to assess the potential habitability of rocky planets. Venus has undergone a runaway greenhouse state where it lost all of its surface liquid water a long time ago. At the inner edge of the habitable zone of any star, where the incident stellar energy is high, planets undergo this runaway phase. This defines a habitability limit for Earth-like planets. So this is similar to what Venus experienced, and with our climate models, we study this state.
Another part of my work uses data from NASA's Kepler mission to calculate the occurrence of potential habitable planets. We published a paper last year that calculates how common are planets that are considered to be Venus analogs, based on their size and incident stellar radiation. We found that Venus analogs are more common than Earth-size planets in their habitable zones. We used fairly simple limits as a first cut, but we hope to improve it in future.
Please provide a webpage link to your research.
http://www3.geosc.psu.edu/~ruk15/
Anything else you'd like to add?
Just that, with current missions like Kepler and future flagship missions like JWST, we have a better chance of characterizing (i.e, detecting various gases in the atmosphere of) Venus-like planets than Earth-like ones, just because of the proximity to their host star.
Erika Kohler
University of Arkansas Center for Space and Planetary Sciences and intern at NASA Goddard Space Flight Center
Visit Erika's Research page
Interview conducted by Lynnae Quick
What do you find most intriguing about the planet?
What I find most intriguing about Venus is how much we still have to learn about it (her) even though it's our closest neighbor. There are just so many questions that still need answered, and every time we do learn something new, there is another question created! Venus will be fascinating for years to come.
Please provide a brief description of your current research.
I test mineral stability under Venusian conditions (temperature, pressure, atmos. constituents) in an effort to find a compositional source for the Venusian radar anomalies. Not only is this providing the next step in understanding these anomalies, but I am gathering new data in respect for thermodynamics and high temp/pressure reactions. Yay science!
Anything else you'd like to add?
Personally, I think people would find laboratory experiments interesting since Venus conditions are so hard to replicate. A short article about Erika's research can be found at http://phys.org/news/2014-10-possibility-metal-venus.html#nRlv.
Giada Amey
University of Washington
Visit Giada's Research page
Interview conducted by Lynnae Quick
What do you find most intriguing about the planet Venus?
There are a lot of things that make Venus interesting! Venus may represent the end state of the evolution of an Earthlike planet, so the planet next door might give us a glimpse at our own world's future. To borrow an analogy from my advisor, Vikki Meadows: if planets are like popcorn, once a planet "pops" into a Venus-like state, you can never get the unpopped kernel back. There may be a lot of these "popped" planets collecting out there in the exoplanet population, so Venus-like worlds may be one of the most common types of exoplanets. I'm also fascinated by Venus because it's such a complicated world, and we have a lot to still learn about it. Just about every time we look at Venus, we discover something new and intriguing. In my own research, I've seen distinctive and unexpected patterns of trace gas abundances in the lower atmosphere, and that's exciting to me because some of these patterns haven't been seen before, and they suggest dynamic processes we haven't studied yet.
Please provide a brief description of your current research.
I used ground-based observations to make maps of the trace gas abundances (H2O, HCl, SO2, CO, OCS) below the Venus cloud deck on the planet's night side. Venus' clouds are actually transparent in the near infrared between 1 and 2.5 microns, so thermal radiation from the surface and lower atmosphere can escape to space and reach our telescopes. With these maps, I looked for spatial correlations between gas species and between gases and the cloud deck opacity. I saw anticorrelation between CO and OCS, which indicates chemical conversion of CO to OCS in the lower atmosphere. Also, interestingly, I saw a surprising banding pattern in my water vapor measurements on three of the nights that might be caused by rainout events in the lower atmosphere. There were also hemispherical dichotomies of several species (CO, OCS, SO2, H2O, and cloud droplet sulfuric acid concentration) that varied over the observation dates. Overall, the Venus lower atmosphere displayed an unexpectedly large amount of variability, and it's just as dynamic as the more easily accessible layers above the clouds.
Is there anything else you'd like to add?
I love being a planetary scientist! We're learning so much today from solar system exploration and from observations of exoplanets, and I can't wait to find out what new surprises are in store for us from future missions!
Kandis Lea Jessup
Senior Research Scientist
Southwest Research Institute (SwRI)
Dr. Jessup's Venus science nugget
Interview conducted by Lynnae Quick
What do you find most intriguing about the planet Venus?
What I find most intriguing about the Planet Venus has two answers. For one, although it is my life-long love for clouds that led me to become an atmospheric scientist, what I love about planetary science is the inter-connectedness of the planet system as a whole. On Venus this is played out by the fact that sulfur- (SO2) gas found in Venus’ atmosphere ultimately originates from active volcanism (which is a geologic process). The formation of Venus’ characteristic dense sulfuric acid (H2SO4) clouds is completely dependent on the photolysis of the SO2 molecule and the presence of H2O in the atmosphere, yet most of the water on Venus has been lost and an active volcanic eruption has yet to be directly observed on Venus — leaving the question of the level of volcanic activity, let alone the mechanism that drives the activity on Venus an open question. As a result, understanding how the H2SO4 cloud formation rate has changed over geologic time, determining if there is still active volcanism on Venus, defining what the impact of such activity may have been on Venus’ geologic and atmospheric evolution, and understanding what is maintaining the current SO2 and H2O abundance in the atmosphere are all issues to be resolved — in short, Venus as a planetary system is one of the great Solar System puzzles yet to be solved, and I always love a good puzzle.
From a “purely” atmospheric composition point of view one of the biggest unanswered questions in Venus science is how the planet maintains a stable CO2 atmosphere. I.e., all the relevant atmospheric composition models and all our empirical knowledge of the chemical reaction rates for the reaction pathways currently defined to be responsible for the maintenance of Venus’ atmospheric composition, imply that the O3P+ O3P reaction leading to the formation of O2 should dominate over the CO+O3P reaction that produces CO2. Thus, no model has ever been able to explain why Venus has a stable CO2 dominant atmosphere; being able to define the missing chemical link that regulates the O2 distribution and sustains the stability of Venus’ CO2 atmosphere is something that intrigues me and motivates my research.
Please provide a brief description of your current research.
As an atmospheric scientist the issues I am most concerned with are: (i) how does the atmosphere function — both chemically and dynamically, (ii) what processes have led to and help to maintain Venus’ past and current climatic conditions, and iii) what can the lessons we learn about the evolution of Venus’ atmosphere (and climate) tell us about the Earth’s atmospheric evolution, past, present and future.
My current research focuses on characterizing Venus’ sulfur oxide cycle via both observation and modeling of the horizontal and vertical distribution Venus’ sulfur-oxide gases (see doi:10.1016/j.icarus.2015.05.027; http://www.issibern.ch/teams/venusso2/project.html). These distributions are balanced by both chemical and dynamic processes occurring in the atmosphere. As implied by the name, the sulfur oxide cycle maintains the budget of S and O in the atmosphere. It is also the chemical cycle responsible for the formation of H2SO4 on Venus, thus it is one of the key chemical cycles operating in Venus atmosphere. A key motivator of my research is the fact that the H2SO4 cloud formation through time is central to understanding Venus’ climate change yet, Venus’ observationally inferred H2SO4 production rate has yet to be replicated by any atmospheric composition modeling efforts. In addition to working towards improving our understanding of the sulfur-oxide cycle as a whole, my research is also motivated by a desire to define how that cycle interacts with Venus’ other chemical cycles, such as the carbon-oxide cycle (responsible for CO2 formation, but linked to O2 formation); the poly-sulfur cycle, and the coupled chlorine-sulfur cycle (see doi:10.1016/j.pss.2007.01.012). The underlying motivation for all of this research is a desire to improve our understanding of how H2SO4, O2, and CO2 have been produced and lost within Venus’ atmosphere over geologic time, so that the mechanisms that drive Venus’ climate evolution can be more accurately defined and understood.
Martin Airey
University of Oxford
Visit Martin's Research page
Interview conducted by Lynnae Quick
Martin is a graduate student in the Department of Earth Sciences at the University of Oxford, where he studies the geology of the terrestrial planets, with an emphasis on the effects of volcanism on planetary systems.
What do you find most intriguing about the planet Venus?
For me, the most intriguing thing about Venus is how the surface and atmosphere have evolved so differently when compared with Earth. The two planets' similarities in terms of size, mass, average density, inferred composition, and proximity to the sun would be suggestive of similar formation and subsequent evolutionary mechanisms. However, the surface environment of Venus is characterised by a hot, dry, dense atmosphere and a complete absence of liquid water at the surface, in contrast to Earth's wet, temperate surface environment with vast oceans and vigorous water cycle. Understanding how their evolutionary histories diverged so dramatically since the formation of the solar system is a fascinating puzzle. As a geoscientist, the properties of the surface and its features, most notably the continent-like tesserae, vast rift systems, and widespread volcanism, instantly raise many questions, but equally provide many clues to Venusian geological processes. The lack of Earth-like plate tectonics on Venus, along with the differing environment, result in a very different volcanic expression at the surface. Understanding Venusian volcanism, and how it impacts on the long-term evolution of Venus' surface and atmosphere, is my current primary research focus.
Please provide a brief description of your current research and how it's linked to Venus science (if this is not obvious).
My current project has been to characterise volcanic processes on Venus, and how they interact with the Venus system, using a number of methods. I firstly designed a custom computer model with which the processes of magmatic ascent beneath volcanic vents on Earth and Venus could be simulated and compared. I considered numerous factors including the geology/magmatic composition, pressure, temperature, geographic elevation, vent geometry, and volatile contribution (magmatic H2O and CO2 gas content). These results were also linked with an existing model to simulate the plume behaviour above ground. These findings made possible the investigation of certain case studies and subsequently the inference of the possibility of detection by orbiting spacecraft. A major finding of this work was the result that, had certain volcanic events observed in the radar images occurred during the Venus Express mission, they may have produced a detectable atmospheric signature, encouraging renewed scrutiny of those datasets.
Another part of the project was designed to complement the modelling by looking for evidence of explosive volcanism using observations of the deposits. The approach was a systematic collection and analysis of radar data for volcanic features on Earth and Venus, with the aim of discovering signatures in the deposits that would enable the identification of the emplacement nature (explosive or effusive) of Venusian deposits based on ground truthing the observations with deposits of a known volcanic origin on Earth. I collected and analysed data describing several radar properties from comparable spacecraft instruments for both planets, which have helped to provide depositional context in terms of textural and compositional information.
Finally, I collected and mapped geospatial information of the occurrence of volcanic features and rift zones on Venus. I performed statistical spatial analysis in order to identify trends in the occurrence of specific features (e.g. clustering) and their relationships with rifts and other feature types, including temporal stratigraphic relationships. The overall result of this work supports the hypothesis that global volcanism has evolved from widespread volcanism centred over numerous small plumes towards a concentration at narrower rift zones with very large volcanoes centred over fewer, larger plumes.
Is there anything else you'd like to add?
Working in the Venus science community has been a personally very enriching experience in my relatively short career so far. This small but outstandingly friendly, inclusive, and supportive community makes discussions and collaborations a very enjoyable and productive process. I am really excited to be a part of this group of pioneering scientists and cannot recommend it more highly.
Candace Gray
New Mexico State University
Visit Candace's Research page
Interview conducted by Lynnae Quick
Candace is a graduate student at New Mexico State University. Her work on Venusian nightglow was recently presented at the Comparative Climatology of Terrestrial Planets II Meeting, which was held at NASA Ames this past September.
What do you find most intriguing about the planet Venus?
The thing I find most intriguing about Venus is its atmosphere. It is unique in the solar system and continually surprising us with new characteristics and behaviors.
Current Research:
My collaborators and I study the Venusian nightglow, specifically the OI (1S-1D) transition at 557.7 nm, referred to as the oxygen green line. The green line is an enigmatic feature on Venus. It is highly temporally variable, observed to be brighter than the Earth's nightglow on some observations and undetectable on others. We hypothesize that this emission is actually an auroral-type emission occurring all across the nightside of Venus and is ignited after large solar storms. Using ground-based observations from Apache Point Observatory, we found a high correlation between coronal mass ejection impacts (large plasma eruptions from the Sun) and increased green line emission. Modelling of the Venusian ionosphere suggests that this emission is due to oxygen ions combining with precipitating solar wind electrons, with increased emission due to the increased flux and energy of precipitating solar wind electrons.
Presenting Venus:
I will be attending the AAS Division of Planetary Science meeting in National Harbor, MD and hope to present a dissertation talk on my work.
Constantine Tsang
Southwest Research Institute
Visit Con's Research page
Interview conducted by Lynnae Quick
What do you find most intriguing about the planet Venus?
I find the dichotomy of Venus fascinating. On one hand, it’s the most Earth like planet; it very close to being the same size and density, with a similar orbit to Earth. It has a significant atmosphere and surface geology. But at the same time, it has no tectonics we know of; the surface has been ravaged by wide spread volcanism, and the atmosphere is completely hostile to life as we know it, and more akin to a gas giant atmosphere than you would think. It is this dichotomy that lends to the idea of Venus being Earth’s “Evil Twin” so well, and why we must understand it far better than we do today.
Current Research:
When I’m studying Venus, I look at the atmosphere. I had my start on the European Venus Express mission (which ended in 2015). My main interest lies in understanding the deepest parts of the atmosphere, from the cloud layer all the way down to the surface. This region, called the troposphere, is hard to study because the global cloud layer obscures this region, but is fascinating because the bulk of the atmosphere is also at these altitudes. To probe this region, I use near-infrared spectra that can be used to study how minor gas species get transported around the planet, and what gets used up during cloud formation.
Onward to Venus!
There are so many fundamental questions about Venus we really don’t have answers to, and going back to Venus not only informs us about Venus itself, but also about how the Earth and our Solar System formed as a whole, and Venus is right next door! The last time NASA was back at Venus was the early 1990’s with the Magellan radar mission, and that revolutionized the way we see the surface of Venus. We need to go back to Venus, and it’s up to the all of us to inspire our community and the public to explore Earths twin planet once more.
If you’d like to be interviewed, or know others who would are ideal candidates to be featured as a part of this series, please contact Lynnae Quick, Lead for the VEXAG Early Career Scholars Focus Group at: [email protected]