Overview:
The 2008 Summer School program will be focussed on the exploration of icy worlds orbiting the giant planets of our Solar System. These satellites are important astrobiology targets in the exploration plans of space agencies as refl ected in the successes of the Galileo mission to Jupiter and the Cassini-Huygens mission to Saturn.
Wandering Poles on Europa
A new study in the May 15th issue of Nature from NAI’s Carnegie Institution of Washington Team reveals that Europa’s poles may not have always been located in the same place. Using images from three NASA spacecraft, Voyager, Galileo, and New Horizons, the study mapped surface features on Europa and matched them with a pattern predicted if Europa had experienced an episode of ~80 degree true polar wander. This movement of the pole and subsequent change in rotation axis is only possible if Europa’s outer shell is decoupled from the core by a liquid layer, so the study also reinforces evidence for the presence of an ocean on Europa.
Continue reading "Recently Published Research from the NAI" »
Presenters: Jody Deming and James Staley (University of Washington)
Date/Time: Monday, March 31, 2008 11:00 AM Pacific
For more information and participation instructions: http://nai.arc.nasa.gov/seminars/seminar_detail.cfm?ID=119
Astrobiology December 2007, 7(6): 1006-1022
http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0156
Europa is a prime target for astrobiology. The presence of a global subsurface liquid water ocean and a composition likely to contain a suite of biogenic elements make it a compelling world in the search for a second origin of life. Critical to these factors, however, may be the availability of energy for biological processes on Europa.
Continue reading "Energy, Chemical Disequilibrium, and Geological Constraints on Europa" »
Astrobiology December 2007, 7(6): 987-1005
http://www.liebertonline.com/doi/pdfplus/10.1089/ast.2007.0075
We examine means for driving hydrothermal activity in extraterrestrial oceans on planets and satellites of less than one Earth mass, with implications for sustaining a low level of biological activity over geological timescales. Assuming ocean planets have olivine-dominated lithospheres, a model for cooling-induced thermal cracking shows how variation in planet size and internal thermal energy may drive variation in the dominant type of hydrothermal system--for example, high or low temperature system or chemically driven system.
Continue reading "Hydrothermal Systems in Small Ocean Planets" »
The NAI Icy Worlds Focus Group met at NASA Ames Research Center on September 20 and 21, 2007. Discussions included a review of the astrobiology potential of four flagship missions to: Europa, Titan, Enceladus, and the Jupiter System. Ron Greeley, the Focus Group co-chair, will share the assessments of the Focus Group with the four mission study leads and NASA Headquarters. [Source: NAI Newsletter]
A special session titled "Return to Europa" will be held at the 2007 fall AGU meeting in San Francisco (Dec. 10-14) [ http://www.agu.org/meetings/fm07 ]. This is an exciting opportunity for presentations on Europa research and analog studies which inform our understanding of this fascinating satellite, and which set the stage for its future exploration. The deadline for abstract submissions is September 6 at 23:59 UT (4:59 pm PDT, 7:59 pm EDT). [Source: NAI Newsletter]
September 20, 2007 to September 21, 2007
The NAI Icy Worlds Focus Group will hold a workshop from September 20-21, 2007 at NASA Ames Research Center. The workshop will concentrate on mission-related astrobiology issues relating to our Solar System’s icy moons such as Europa, Titan, and Enceladus. Participants will share their work, making presentations and assessments of the four NASA-sponsored mission studies, and considering the measurements and instruments appropriate for astrobiological exploration of icy objects.
New research from NAI's SETI Institute Team published online in Icarus today outlines the empirical range of salt concentrations permitted for Europa's ocean. Solutions within the range imply high, near-saturation salt concentrations and require a Europan ice shell of less than 15 km thick, with a best fit at 4 km ice thickness. The paper examines the implications for subsurface habitability. [source: NAI Newsletter]
Speaker: Tim Raub (Yale University), Date/Time: Monday, February 26, 2007 11AM PST
Background: Using atmospheric chemical models of a Snowball Earth, scientists from NAI's Alumni Virtual Planetary Laboratory Team showed that, during long and severe glacial intervals, a weak hydrological cycle coupled with photochemical reactions involving water vapor would give rise to the sustained production of hydrogen peroxide. The peroxide, upon release from melting ice into the oceans and atmosphere at the end of the snowball event, could mediate global oxidation events.
Cassini Radar Finds Hydrocarbon Lakes on Titan
"The Cassini spacecraft, using its radar system, has discovered very strong evidence for hydrocarbon lakes on Titan. Dark patches, which resemble terrestrial lakes, seem to be sprinkled all over the high latitudes surrounding Titan's north pole. Scientists have speculated that liquid methane or ethane might form lakes on Titan, particularly near the somewhat colder polar regions."
Towards the end of our summer expedition while flying back to Eureka from our camp on Axel Heiberg, I spotted a lake with what appeared to be green ice on it.
Continue reading "Green ice, Ravens, Ice Caves and the Movie ‘Contact’" »
Undersea Vehicles to Study Formation of Gold and Other Precious Metals On the Pacific Ocean Floor, WHOI
"The joint expedition includes a 32-day WHOI research program funded by the U.S. National Science Foundation to the Pacmanus vent sites in the Eastern Manus Basin. The remotely operated vehicle Jason will be used to survey and map the vent areas around an Ocean Drilling Program hole drilled in 2000."
Following on the recent Cassini discoveries of geysers, organics, and excess heat emanating from the south polar terrain of Enceladus, and the exciting implications of these findings for possible subterranean chambers of liquid water, we are forming an Enceladus Focus group to begin a community-wide conversation about this fascinating moon.
The NAI sponsored workshop of the Europa Focus Group at NASA Ames Research Center, from February 27 - 28, 2006, involvied 115 participants. Presentations from this successful meeting are now available at: http://astrobiology.asu.edu/focus/europa/discuss/discuss.html