Fall 2014

An Update from our Students

By Giada Arney
Student Representative, UW Astrobiology Steering Group

2014 has been an exciting year for astrobiology.  The number of known exoplanets has climbed to well over 1000.  One of these planets, Kepler-186f, is similar in size to Earth and orbits in its star’s habitable zone.  Closer to home, Curiosity continues to rove across the Martian surface making amazing discoveries, and the Rosetta/Philae mission gave us up-close photos from the surface of a comet for the first time.  At UW, astrobiology students got the chance to study the ocean aboard the Thomas G. Thompson research vessel on this year’s astrobiology workshop. UW astrobiology students are advancing our knowledge of Earth and its biosphere, worlds across our solar system, and distant exoplanets.  Here are some of the projects UW astrobiology students are tackling.

Life On Earth

Understanding life on Earth is the first step to understanding life elsewhere.  Anna Simpson is studying high alpine soils to examine how nutrient cycling and microbial communities shift when snow melts.  Gordon Showalter is looking at bacterial motility in sea ice and other cold environments, and trying to understand how microbial movement that might translate as a biomarker. Chloe Hart is investigating the thermodynamics of microbial growth to better understand energy budgets for different types of microbes and metabolisms. This work may help to guide our search for habitable worlds elsewhere with a “follow the energy” approach. Michael Kipp is studying the coevolution of the biosphere and Earth's atmosphere using microbial experiments and isotope analysis of sedimentary rocks. Chantz Thomas is studying the molecular machinery of life and is designing novel biological structures through computational molecular engineering.

Earth Environments

Earth’s biosphere is closely linked to its environment, and UW graduate students are working to understand how the Earth system has changed over time.  Regina Carns is studying modern Antarctic ice along with laboratory experiments and computer models to figure out how much light gets reflected by different kinds of ice to improve climate models and our knowledge of how Earth’s climate has evolved over geologic time.  Matthew Koehler is studying rocks from the Archean (4-2.5 billion years ago) and Proterozoic (2500-541 million years ago) to see how nitrogen cycling has changed both spatially and through time. Implications of this work include insights into eukaryotic evolution, as well as atmospheric evolution of oxygen and nitrogen.  Joshua Krissansen-Totton has been exploring thermodynamic disequilibrium in planetary atmospheres as a potential biosignature. He also completed a statistical analysis of the carbon isotope record and discovered that the record is too noisy to determine whether changes in organic burial can explain the rise of oxygen on Earth.  Meg Smith is working on biogeochemical modeling of the early Earth's oceans and atmospheres to determine how the redox state of the atmosphere and ocean changed from the early Archean through to the late Neoproteorzoic (1000-541 million years ago). Giada Arney is examining how hazes in the Archean atmosphere may have impacted Earth’s ancient climate.

Other Solar System Worlds

Many UW graduate students have focused their efforts on better understanding Mars. Steven Sholes has been using a computer model to investigate whether volcanoes on Mars could have changed the atmosphere - making it more habitable in the past - and is also searching for signs of ancient oceans.  Meg Smith used a computer model to prove that perchlorates, strange salts discovered across the surface of Mars, probably did not form through chemical reactions in the atmosphere.  Jonathan Bapst is studying the distribution of ground ice on Mars, which is controlled by the amount of water vapor in the Martian atmosphere.  Elena Amador is using satellite imagery of the Martian surface to identify areas that once may have been altered by water in the distant past.  Mars is not the only planet UW students are studying, though. Matt Tilley is working to model and analyze the effects of variable plasma pressures in Saturn's magnetosphere to see they might affect Titan's habitability and atmospheric evolution.

Distant Exoplanets

The number of known exoplanets is growing rapidly, and UW astrobiology students are at the forefront of developing techniques to understand these worlds. Jacob Lustig-Yaeger is working to determine how to detect molecules in the atmospheres of exoplanets to prepare for the coming months, years and decades when we will peer into the atmospheres of planets increasingly more like our Earth.  Brett Morris is using large ground-based telescopes to detect signatures of molecules in the atmospheres of giant exoplanets, and these techniques may one day be used to search for biosignatures in the atmospheres of super-Earths.  Amit Misra, who just graduated, , has been developing methods to characterize clouds and hazes of transiting exoplanets as well as working on a method to detect volcanic eruptions on exoplanets.  Russell Deitrick is studying the orbital dynamics of exoplanets to understand how the climates of potentially habitable planets can be affected by the gravitational forces of other nearby worlds.  Rodrigo Luger is investigating the habitability of planets around stars less massive than the Sun, focusing on their atmospheric evolution and on the stability of their surface water.  Eddie Schwieterman is studying types of surface biogsignatures we might be able to observe on distant planets and is modeling how biogenic gases such as O2 may be produced abiotically in some circumstances, potentially leading to false positive detections of life.  Giada Arney is using computer models to study how hazes in early Earth’s atmosphere may impact our ability to glean information from similarly hazy, Earthlike exoplanets.

Education and Public Outreach

Engaging with the wider community is an important part of disseminating the incredible discoveries in astrobiology to the public. Matt Tilley and Meg Smith are taking part in the Pacific Science Center's Science Communication Fellowship as part of an Astrobiology outreach effort. Regina Carns gave a Seattle Nerd Nite talk on ice physics and also volunteers at the Pacific Science Center. Meg Smith, Joshua Krissansen-Totton, and Steven Sholes traveled to both Vashon Island and Tacoma to speak to elementary and middle school students about astrobiology and Mars.  Chantz Thomas advises the Museum of Flight's Board of Directors through his service on the Museum's Future Leaders Committee. On campus, Giada Arney, Eddie Schwieterman, Brett Morris, and Russell Deitrick have given planetarium shows to numerous K-12 groups through the UW planetarium to help inspire the next generation of scientists. Wolf Clifton is developing an online exhibit set to debut in April 2015 for his Masters in Museology, titled "Beyond Human: Animals, Aliens, and Artificial Intelligence," which examines the human relationship to other creatures. Kelly Hillburn, who will soon graduate with her PhD,worked with Dr. Woody Sullivan on her astrobiology research rotation in summer 2014 focusing on the history of astronomy and geology circa 1770-1810, exploring the connections between the work of astronomer William Herschel and his contemporary natural historians.  Michael Kipp has been teaching an astrobiology class for middle school students at UW's Robinson Center for Young Scholars.

Photo: Graduate students aboard the UW Research Vesssel, The Tommy G. Thompson, for this year's workshop. Last row (left to right): Shelly Carpenter (Oceanography), Chantz Thomas (Chemistry), Paul Kintner (ESS), Brendan Philip (Oceanography), Russell Deitrick (Astronomy), Michael Kipp (ESS), Matt Tilley (ESS), Rodrigo Luger (Astronomy), Steven Sholes (ESS), Eddie Schwieterman (Astronomy), Josh Krissansen-Totton (ESS), Matthew Koehler (ESS), Hannah Glover (ORCA Lab Field Engineer), Aaron Brewer (ESS), Jon Bapst (ESS). Middle row: Jim Postel (Ship’s Senior Marine Technician), Prof. Jody Deming (Oceanography), Prof. John Mickett (Oceanography), Prof. David Catling (ESS), Anna Simpson (SEFS), Diana Windemuth (Astronomy), Brett Morris (Astronomy), Chloe Hart (ESS), Evan Firth (Oceanography), Prof. Jan Newton (Oceanography), Osa Igbinosun (A&A), Loren Tuttle (Ship's Second Marine Tech), Orlando Thompson (TGT Crew Member). Front row: Jacob Lustig-Yaeger (Astronomy), Prof. Rory Barnes (Astronomy), Megan Smith (ESS), Elena Amador (ESS), Rachel Vander Giessen (APL), Zöe Parsons (ORCA Lab Field Engineer), Max Showalter (Oceanography), Jaci Saunders (Oceanography).

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