"How do asteroids and meteorites relate to the origin and composition of the earth?"
-
Seminar Detail
Exotic Earths: Hot Jupiters, Tidal Evolution, and Ocean Planets
Presenter: Sean Raymond
October 16, 2007 02:30 PM Pacific
Planets like Earth form via collisional accumulation of smaller bodies in circumstellar disks. However, there exist systematic differences between the formation environment of Earth-like planets around other stars and that of the Solar System. For example, short-lived radionuclides (SLRs) like 26Al were an important heat source in the Solar System and may have been derived from a nearby supernova. However, SLRs have variable abundances in protoplanetary disks because of orbital variations within stellar clusters which determine the proximity to supernovae. The quantity of SLRs can be directly tied to the water abundance of terrestrial planets. In addition, the habitable zones of low-mass stars are very close-in, which affects the ability of habitable planets to have large masses or retain water, and can also cause large orbital changes via tidal dissipation. About 60 "hot Jupiters" are currently known; these giant planets likely formed farther from their stars and migrated inward through the habitable zone. Ocean-covered planets are often able to form in the "wake" of a migrating giant planet.
Participation Instructions
With a Polycom....RSVP to Marco Boldt (Marco.Boldt@nasa.gov) and connect to WebEx as instructed below. If you need Polycom help during the live event, message Marco Boldt in WebEx.
The slides from the seminar can be accessed real-time using WebEx at:
https://nasa.webex.com
Enter the meeting number: 929 696 026 Hit the "join now" button.
Enter your name or site name (this is not an assigned log-in name, please use your institution name or your first and last name), email and the password: raymond123* (case sensitive)
If you've never joined a WebEx meeting before, please allow an extra 5-10 minutes to install the plug-in.
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/AB071016-01.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
