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"Has there been any evidence that human life has ever lived on any other planet besides Earth?"
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Seminar Detail
Formation of Habitable Planetary Systems: Are We Normal?
Presenter: Sean Raymond and Avi Mandell ()
November 27, 2006 11:00 AM Pacific
For a planet to be potentially habitable over long timescales, it must 1)
have a stable orbit in the "habitable zone" (HZ); 2) have sufficient mass to
sustain plate tectonics and maintain an atmosphere; and 3) have a substantial
water content. Habitable planets are thought to form from a swarm of rocky/icy bodies in
circumstellar disks, and it is this process which determines whether these
"habitability criteria" will be met. We will review this process in the context of the
formation of Earth and the Solar System, and examine the conditions needed
to form habitable planets around other stars. Of particular importance is the
presence and location of giant planets, which form more quickly than terrestrial
planets and can strongly influence the final stages of terrestrial planet
formation. We discuss models of terrestrial planet formation in systems with different
configurations of giant planets, and we derive limits on habitable planet formation that
suggest that about one third of the known sample of giant planet systems could harbor
a potentially habitable planet. The formation and final characteristics
of habitable planets formed in these simulations depend strongly on the
dynamics of the giant planets, and we predict the existence of a large variety
in the masses, orbits and compositions of Earth-like planets around other
stars.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/2006/AB061127-01.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