"What would earth look like without water on it? What would be the shape of the 'piece of rock' that would remain?"
-
Seminar Detail
Infrared Spectra of Extrasolar Planets
Presenter: Drake Deming ()
March 26, 2007 11:00 AM Pacific
Two independent scientific groups have recently reported the first spectroscopy of planets orbiting other stars, using the Spitzer Space Telescope. The planets (HD 209458b and HD 189733b) are "hot Jupiters" orbiting within 0.05 AU of solar-type stars, and with orbital periods from 2.2 to 3.5 days. Their orbital planes are close to our line of sight, so both planets pass in front of ("transit"), and disappear behind their stars, once each orbit. The Spitzer measurements were made by subtracting the spectrum of each star - with the planet in eclipse - from the combined infrared light of the system, to yield the infrared spectrum of the planet alone. Theorists expected that absorption by hot water vapor would dominate the spectra of these planets in the 7- 14-micron wavelength region. However, neither planet shows this expected signature, indicating that some process is masking the water absorption. One planet (HD 209458b) shows spectral features appearing in emission above a hot thermal continuum, indicating the likely presence of silicate clouds, and possibly more exotic compounds, at high altitudes in the planet's atmosphere.
The future launch of the James Webb Space Telescope will allow us to extend these measurements to spectra of transiting terrestrial planets in the habitable zones around lower main sequence stars.
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, call the videoconferencing help-desk at (650) 604-6412
The slides from the seminar can be accessed real-time using WebEx at:
https://nasa.webex.com
Enter the meeting number: 928 244 611 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: deming123* (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/AB070326-01.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
Team Overview Seminars: Each of the NAI teams will be giving one hour overview seminars that describe the work they will be performing as members of the NAI. These seminars, which will be broadcast via videoconference and web, will provide an opportunity to find out more about the science, EPO and other activities being performed by the NAI teams.
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. These seminars are open to all, including the general public; however, the target audience is researchers and students who are engaged in astrobiology. While the seminars are technical in nature, speakers are encouraged to develop presentations that can be understood by colleagues from a variety of disciplines across the field. The talks are typically 50 minutes long, with time at the end for questions and discussion.
The Forum for Astrobiology Research (FAR) seminar provides an opportunity for graduate students to present their research results, and to meet as a student community for mutual encouragement and support. FAR science presentations are typically 20-30 minutes each, with several students presenting during one virtual event. On occasion, the FAR seminar will be devoted to group discussion and planning activities.
The University of Washington seminar series is hosted by the NAI VPL team from their campus in Seattle. NAI provides technical support for the seminar series and produces podcasts of the presentations. The talks are typically 50 minutes long, with time at the end for questions and discussion.
Other virtual seminars, such as workshops and summer student presentations, are hosted by NAI. These are typically scheduled as needed and vary in length, content, and target audience.
