LPI Seminar Series
The LPI Seminar Series brings prominent scientists to the LPI to present on a broad array of scientific disciplines that advance our understanding of the solar system. The seminar series, which began in September 1969, has brought many notable contributors from numerous research and academic institutions to the LPI. Seminars are typically held on Thursdays from 3:30-4:30 p.m. CST, but dates and times are subject to change. All seminars will be held virtually until further notice.
Sign up for LPI Seminars to receive email notifications of upcoming seminars and details on how to join the virtual seminar. For more information, please contact Prajkta Mane (firstname.lastname@example.org) and Sean O’Hara (email@example.com).
See also the Rice University Department of Physics and Astronomy Colloquia and the Department of Earth Science Colloquia pages for other space science talks in the Houston area.
Thursday, January 7, 2021 - Virtual, 3:30 PM
Craig Hardgrove, Arizona State University
Searching for Lunar Water with LunaH-Map: Tiny Interplanetary Spacecraft With Big Science and Exploration Goals
LunaH-Map is a new type of NASA planetary science mission manifested for launch on Space Launch System Artemis-1. Following in the footsteps of the MarCO cubesat's successful interplanetary mission, the LunaH-Map spacecraft is a miniaturized, shoebox-sized, interplanetary spacecraft that will use a small ion propulsion system to navigate into lunar orbit and a neutron spectrometer to map enrichments of hydrogen across the lunar South Pole. The maps produced by LunaH-Map will help constrain the amount of hydrogen within permanently shadowed regions, which will inform our understanding of sources and sinks for polar volatile deposits, as well as planning future lunar exploration missions.
To R.S.V.P., visit http://ow.ly/JW5b50CZI4h
Thursday, January 14, 2021 - Virtual, 3:30 PM
David A. Kring, Lunar and Planetary Institute
A Subterranean Hydrothermal System and Microbial Nursery Beneath the Floor of the Chicxulub Impact Crater
An expedition sponsored by the International Ocean Discovery Program and International Continental Scientific Drilling Program recovered rock core from the peak ring of the ~180 km-diameter Chicxulub impact crater. Mineral assemblages in the core indicate the crater hosted a substantial and long-lived hydrothermal system. Furthermore, sulfur isotope compositions of pyrite framboids that precipitated in the hydrothermal system indicate it was inhabited by sulphate-reducing thermophilic organisms. The findings support the impact origin of life hypothesis, which posits prebiotic chemistry and the early evolution of life occurred in similar impact-generated systems during the Hadean on Earth and potentially in other planetary systems where similar hydrothermal systems are generated. To R.S.V.P., visit https://bit.ly/3ouPVuT
Thursday, January 21, 2021 - Virtual, 3:30 PM
Casey Honniball, Goddard Space Flight Center
A Tale of Lunar Water
For decades the lunar surface was believed to be anhydrous, however, reports by three independent spacecraft in 2009 changed this view when they detected a 3 µm hydration band on the Moon. The 3 µm absorption band is attributed to hydroxyl (OH) and possibly molecular water (H2O). The band exhibits variations with lunar time of day, temperature, soil maturity, and composition that has been interpreted as variations in water concentrations.
Data from an infrared spectrometer, the Moon Mineralogy Mapper (M3) onboard the Chandrayaan-1 spacecraft, is widely used to study the 3 µm band, its spectral range, however, only covers half the hydration band. Due to the limited wavelength range of M3, variations of hydration has been called into question. To investigate the validity of variations in the 3 µm band we used the Spex infrared cross-dispersed spectrograph at the NASA InfraRed Telescope Facility (IRTF) at Maunakea Observatory in Hawaiʻi. Our improved data showed that the variation in hydration is real.
But is hydroxyl or water responsible for the variations? Distinction between OH and H2O from spacecraft measurements at 3 µm is difficult due to their similar spectral properties. We have developed a new approach for unambiguous detection of the water molecule on the sunlit lunar surface. At 6.07 µm the fundamental H-O-H bend of H2O is exhibited and is strictly due to H2O without contribution by OH. The only current observatory capable of 6 µm observations of the Moon at 6 µm is the Stratospheric Observatory For Infrared Astronomy (SOFIA). Using data from SOFIA we report the first direct detection of the water molecule on the sunlit lunar surface.
To R.S.V.P., visit Https://rb.gy/7z77ll
Thursday, January 28, 2021 - Virtual, 3:30 PM
Cecilia W.S. Leung, Jet Propulsion Laboratory
Regional Atmospheric Dynamics of Water in Valles Marineris, Mars
Water vapor in the planetary boundary layer is substantially influenced by local topographic gradients. Using a mesoscale atmospheric model, we investigate the convergence of regional moist air masses that forces asymmetries between the day-night concentrations of water in the canyon system. I will discuss the conditions under which water ice fogs may form inside Valles Marineris, and the implications for deliquescence and brines that may result from an atmospheric reservoir.
To R.S.V.P., visit https://rb.gy/mql0ye
Thursday, February 11, 2021 - Virtual, 3:30 PM
Yaray Ku, Harvard University
Potassium isotope anomalies in meteorites inherited from the protosolar molecular cloud
Potassium (K) and other moderately volatile elements are depleted in many solar system bodies relative to CI chondrites, which closely match the composition of the Sun. These depletions and associated isotopic fractionations were initially believed to result from thermal processing in the protoplanetary disk, but so far, no correlation between the K depletion and its isotopic composition has been found. In this talk, I will present our high-precision K isotope data correlated with other neutron-rich nuclides (e.g., 64Ni and 54Cr), suggesting the observed 41K variations of a nucleosynthetic origin. In addition, I will present new K isotope data from individual chondrules and matrix analysis during this talk. Our data support that K isotope anomalies are inherited from an isotopically heterogeneous protosolar molecular cloud, and were preserved in bulk primitive meteorites.
To R.S.V.P., visit https://rb.gy/jtztzn.
Thursday, February 25, 2021 - Virtual, 10:00 AM
Dept. of Earth Sciences
Jahnavi Punekar, IIT Bombay
The End-Cretaceous Planktic Foraminifera Crisis Linked to Ocean Acidification?
The Cretaceous-Palaeogene boundary event (K-Pg; ~66 Ma) is well known for the demise of >70% life on Earth, including the non-avian dinosaurs. It is one of the BIG FIVE mass extinctions of the Phanerozoic, the only one linked with two triggers- the Chicxulub impact (Yucatan peninsula, Mexico) and Deccan volcanism (India). Recent high-precision U-Pb ages constrain Deccan volcanism between ~66.3 Ma and ~65.6 Ma1. Mercury chemostratigraphy coupled with planktic foraminifera biostratigraphy have enabled unprecedented correlation of the timing, tempo and extent of the end-Cretaceous faunal, climatic and environmental perturbations with Deccan eruptions2. In the main Deccan province (India), the K-Pg boundary is now inferred to be at the top of the Poladpur Formation - a likely catastrophic high-volume eruptive event that lasted <100 kyr1. Proximal K-Pg sequences in the Krishna-Godavari basin intertrappeans (India) document >90% planktic foraminifera species going extinct in response to correlative lava megaflows3. The distal western Tethyan sites reveal a “poor-carbonate-preservation” interval4 with high planktic test fragmentation, increased abundance of opportunist taxa (Guembelitria spp.) and intraspecific dwarfing immediately preceding the K-Pg boundary. Experimental validation of preservation-based proxies lends support to this end-Cretaceous acidification hypothesis. Coeval bulk-rock low magnetic susceptibility and peak mercury signals firmly tie this acidification to ongoing Deccan volcanism5. The biological, taphonomic and geochemical evidence strongly support an ocean acidification interval that persisted for <52 kyr (~2 precession cycles) prior to the K-Pg boundary. The age, duration and nature of this acidification event are better explained by recurrent pulses of Deccan volcanism than the geologically instantaneous Chicxulub impact.
To R.S.V.P., visit https://rb.gy/lgjqst.
Thursday, March 4, 2021 - Virtual, 10:00 AM
Tim Lichtenberg, Oxford University
Thursday, March 11, 2021 - Lecture Hall, 3:30 PM
Roger Fu, Harvard University
Thursday, March 25, 2021 - Virtual, 3:30 PM
Mike Thorpe, Johnson Space Center
Thursday, May 6, 2021 - Virtual, 3:30 PM
Elizabeth Frank, First Mode
Thursday, May 27, 2021 - Virtual, 3:30 PM
Jim Bell, Arizona State University