"Why was it significant that the Phoenix lander found ice on Mars? Haven't we known for some time that Mars has ice caps at its poles?"
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Seminar Detail
Microbial Activities in Deep Subseafloor Sediments
Presenter: Steven D'Hondt ()
April 30, 2007 11:00 AM Pacific
Recent studies by URI investigators and our collaborators have advanced understanding of Earth’s subsurface life in several ways. These advances include the following discoveries: (1) respiration per subseafloor cell is much lower than canonical estimates of respiration required for cell maintenance; (2) thermodynamic cooperation sustains complex subsurface communities for millions of years; (3) subseafloor biomass and predominant redox activities vary predictably with the chlorophyll content of the surface ocean; (4) subseafloor redox activities ultimately affect the chemistry of the ocean and atmosphere; and (5) Earth’s subsurface biomass is much smaller than the canonical estimate. Preliminary data suggest that hydrogen from radiolysis of water may be a significant food source for microbial communities in the low-activity sediments that characterize much of the open ocean.
Participation Instructions
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Without a Polycom...There are two ways to participate:
1) You can listen to the seminar on the telephone while viewing the slides in WebEx (see WebEx instructions above). The NASA conference phone number will be displayed when joining the WebEx meeting.
2) You can watch the Realplayer webcast at: http://vanseg-1.arc.nasa.gov/2007/AB070430-01.ram and view the slides in WebEx (see WebEx instructions above) There is a 30 second delay for the webcast, so you will need to control the slides manually using the arrow buttons in WebEx. Questions for the speaker can be posted in the WebEx chat area to be answered at the end of the talk. Do not try to watch the Realplayer webcast at the same time as the Polycom or the phone. Due to the delay in the webcast, it will sound awful, unless you like dissonance.December 21, 2007
The Director’s Seminar series features talks from scientists who are invited by the NAI Director to present their research results to the community. A primary goal of the seminars is to encourage interdisciplinary collaboration across NAI teams and within the astrobiology community at large.
Team Overview Seminars describe the work of the fourteen NAI teams and NAI Central. They offer an opportunity to find out more about the science, E/PO and other activities being performed by the NAI teams and the NAI Central office.
The Forum for Astrobiology Research (FAR) provides an opportunity for graduate students to present their research results and to meet as a student community for networking and mutual support.
The University of Washington seminar series is hosted by the NAI Virtual Planetary Lab (VPL) team from the UW campus in Seattle.
