On August 19, we held our second Roundtable on Current Issues. The session, entitled “Oceans in the Solar System: exploring the origin of life and habitability of water bodies on Mars, Europa and Earth”, discussed the evidence for water bodies outside the Earth, and their implications for the origins of life and planetary habitability. Our first speaker was Dr. Timothy Goudge from the University of Texas (UT) at Austin and the UT Center for Planetary Systems Habitability (CPSH). He reviewed the current geologic and geochemical clues that point towards a Martian surface that may have been entirely covered by rivers, lakes, and oceans. He also discussed our next steps forward in planetary exploration, namely the scientific goals of NASA’s Mars 2020 Perseverance rover, which will explore an ancient water body. Dr. Krista Soderlund, also from UT Austin and UT CPSH, journeyed us further into the depths of the Solar System to explore the present-day possibility of oceans in Europa, one of Jupiter’s icy moons. Her work comprises planetary fluid dynamics and geophysical numerical simulations, and will play a key part in the upcoming NASA Europa Mission. Lastly, Dr. Mary Voytek, Director of the NASA Astrobiology Program, focused on the possibility of life in the exciting habitats outlined by Dr. Goudge and Dr. Soderlund.
Agenda:
- 1:00 PM UTC – Welcome address and introductions
- 1:10 PM UTC – Timothy Goudge
- 1:40 PM UTC – Krista Soderlund
- 2:10 PM UTC – Mary Voytek
- 2:40 PM UTC – Q&A Session
- 2:55 PM UTC – Closing remarks
Speakers
Timothy A Goudge
The Geologic Record of Lakes, Seas, and Oceans (?) on Mars
Decades of planetary exploration have revealed widespread geologic evidence that Mars had a period very early in its history in which liquid water flowed across the surface. While this is the case, many of the details about this period of martian history remain a mystery. In this talk I will provide a brief overview of some of the lines of evidence for water on ancient Mars, with a focus on the record of large standing bodies of waters, such as lakes, seas, and the possibility of an early martian ocean. I will also discuss major outstanding questions in the Mars science community on the details of the ancient martian surface environment. A key point of interest for early Mars is that the time period of early water activity overlaps with the earliest signs of life on Earth, and I will also discuss some of the next steps in the search for ancient life on Mars.
Dr. Tim Goudge is an Assistant Professor in the Department of Geological Sciences within the Jackson School of Geosciences at the University of Texas at Austin. Dr. Goudge heads the UT Austin Planetary Surface Processes Group, which works to understand the role of surface processes in controlling the evolution of planetary landscapes. Dr. Goudge’s research focuses on the use of remote sensing data to study the signature of surface processes recorded in the topography, mineralogy, and sedimentary rock record of Mars, Earth, and other planetary bodies. Past work has involved studies of the record of ancient lake basins on Mars, and use of high-resolution images and topography to unravel past environments from the martian sedimentary rock record. Dr. Goudge has also worked extensively on the Jezero crater delta, the upcoming field exploration site for NASA’s Mars 2020 Perseverance rover. Prior to UT, Dr. Goudge received a BSc in geological engineering from Queen’s University in Kingston, Ontario, and a ScM and PhD from Brown University in Providence, Rhode Island.
Krista Soderlund
Exploring the Icy Ocean World Europa
Europa is an icy ocean world orbiting the planet Jupiter. This satellite, comparable in size to the Earth’s moon, has long been considered a potential abode for life since it maintains a global liquid water ocean sandwiched between an outer icy shell and rocky mantle below. Much of what we know about this satellite is derived from observations by the Galileo spacecraft that orbited Jupiter from 1995 to 2003, complemented by ground-based observations, numerical models, laboratory experiments, and terrestrial analogs. In this talk, I will discuss the evidence for this subsurface ocean, what we know and don’t know about it, and plans for future exploration. In particular, NASA’s upcoming Europa Clipper mission will conduct detailed reconnaissance of the moon and investigate whether it could harbor conditions suitable for life.
Dr. Krista Soderlund is a Research Scientist at the Institute for Geophysics within the Jackson School of Geosciences at the University of Texas at Austin. Dr. Soderlund’s research focuses on planetary interiors, fluid dynamics, and magnetohydrodynamics. Her recent projects primarily use numerical simulations to model ocean and ice shell dynamics of Jovian and Saturnian satellites, convection and magnetic field generation within the interiors of Uranus and Neptune, and the origin of Mercury’s magnetic field. Dr. Soderlund is a science team member of the REASON radar instrument on NASA’s Europa Clipper Mission, the Neptune-Triton Planetary Mission Concept Study, and the Oceans Across Space and Time project. Dr. Soderlund received BS degrees in Physics and Space Sciences from the Florida Institute of Technology, and a MS and PhD in geophysics and space physics from the University of California Los Angeles.
Mary Voytek
Water, water everywhere, but where besides Earth might we find life?
In many ways the search for evidence of life beyond Earth has been linked to ocean exploration and discovery. In 1975-76, NASA sent life detection experiments on two Viking landers to the surface of our nearest neighbor Mars. Once with a climate similar to Earth, Mars is believed to have had, and lost more than an Earth’s ocean from its surface as it evolved to the cold desert we see today. Meanwhile (1977), Earth scientists made an astonishing discovery at depth on the Galápagos Rift that would forever change our understanding of life on Earth. Their discovery of an oasis of life at hydrothermal vents supported entirely without sunlight but by chemosynthesis set off decades of fruitful exploration into extreme environments that redefined the limits to life and opened up a myriad of possibilities for potential extraterrestrial habitats. I will discuss how these two very important expeditions paved the way for our current strategies for exploring life in oceans beyond Earth.
Dr. Mary A. Voytek is the Senior Astrobiologist at NASA and directs NASA’s Astrobiology Program, which is interested in the origins, evolution, and distribution of life in the Universe. Before joining NASA in 2008 she headed the US Geological Survey’s Microbiology and Molecular Ecology Laboratory in Reston Virginia. Dr. Voytek’s primary research interest is aquatic microbial ecology and biogeochemistry. She has studied environmental controls on microbial transformations of nutrients, xenobiotics, and metals in freshwater and marine systems. She has worked in several extreme environments including Antarctica, the arctic, hypersaline lakes, deep-sea hydrothermal vents, and terrestrial deep- subsurface sites.
Moderator
Frank Muller-Karger
Frank Muller-Karger is a biological oceanographer who conducts research on the diversity of life in the sea, factors that drive diversity and production, and the relevance to people. He combines traditional oceanographic methods and satellite remote sensing to study patterns of variation of phytoplankton and of coastal wetlands. Frank looks for partnerships that seek to integrate biological observations into existing and planned ocean observing systems, in a way that all disciplines benefit and to provide solutions to social and economic problems. Frank is co-chair of the GEO Marine Biodiversity Observation Network (GEO MBON) of GEO BON, is involved in the UNESCO Intergovernmental Oceanographic Commission’s (IOC) Global Ocean Observing System (GOOS) Bio-Eco panel, the IOC’s Ocean Best Practices Steering Committee, and leads the OceanObs Research Coordination Network (RCN). He holds B.S., M.S. and Ph.D. degrees in marine science and a Master in management. He has authored or co-authored over 250 peer-reviewed scientific publications.
Image Gallery
Dr. Timothy Goudge - Exposed layering within the Jezero crater western delta deposit. Top figure shows an overview image of the delta outcrop, and bottom figure shows a perspective view of exposed delta layering (look direction shown by white 'V' in top figure). The Jezero crater paleolake basin is the landing site for the upcoming NASA Mars 2020 Perseverance rover.
Dr. Timothy Goudge - Topographic map of an example paleolake basin on Mars, with river valleys flowing into an ancient, degraded crater basin (inlets), and a river canyon draining away from the basin (outlet).
Dr. Krista Soderlund - Jupiter's moon Europa has an outer icy crust supported by a subsurface ocean that is roughly 100 km thick, an intermediate rocky mantle, and a central iron core. Credit: NASA/JPL.
Dr. Krista Soderlund - The Europa Clipper mission will investigate Europa's habitability by answering questions like: Does the moon have an ocean and, if so, how thick is the ice above it? Is material exchanged between the surface and the ocean? What are the chemistry and origin of non-ice materials on the surface? Are there areas of recent or current geological activity? Credit: NASA/JPL-Caltech
Dr. Krista Soderlund - This rendering shows the temperature field in a simulation of Europa’s global ocean dynamics, where hot plumes (red) rise from the seafloor and cool fluid (blue) sinks downward from the ice-ocean interface. More heat is delivered to the ice shell near the equator where convection is more vigorous. Credit: K. M. Soderlund