SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 1 - January 13, 2006

91 LUNAR AND PLANETARY SCIENCE AND EXPLORATION
Includes planetology; selenology; meteorites; comets; and manned and unmanned planetary and lunar flights.

For spacecraft design or space stations see 18 Spacecraft Design, Testing and Performance.

20060000068 Montreal Univ., Quebec, Canada

The Gemini Deep Planet Survey (GDPS)

Doyon, Rene; Gemini Focus: Newsletter of the Gemini Observatory; December 2005, pp. 35-37; In English; See also20060000060; Copyright; Avail.: Other Sources

This year marks the tenth anniversary of what will undoubtedly be declared one of the major scientific discoveries of the20th century: the detection of the first planet outside the solar system. Thanks to novel and more precise instrumentation, 51Pegasus b was discovered by the Doppler technique-measuring the tiny reflex movement of a parent star induced by an orbiting planet.

Today, no less than 168 planets in 144 planetary systems have been identified by a related technique that uses radial velocity measurements. These objects include the now-famous transiting system HDzog@b, whose light curve hasprovided a direct measurement of the planet s radius. Even its atmospheric constituents have been probed by Hubble SpaceTelescope (HST) at optical wavelengths. More recently, Spitzer Space Telescope made a direct detection of the infraredradiation from the planet.

Aside from the important statistical fact that gas giant planets do exist in more than 7% of nearbyF, G, K and M (main sequence) stars, and more preferably around metal-rich ones, the wealth of radial velocity data has alsounveiled the existence of hot Jupiters -gas giant planets orbiting very close to their parent star in scorching hot regions clearly not conducive to the formation of Jovian planets (which are made mostly of volatile gas). It is now believed that those worlds were likely formed at larger distances beyond the so-called snow line, (where water and other volatiles would condense outof the cloud of gas and dust that form a planetary system) and migrated inward either through disk-planet dynamicalinteraction and/or planet-planet gravitational interaction. Clearly, it has been a very busy and exciting first decade for thestill-infant discipline of exoplanetary science.

We have yet to probe and search at relatively large (greater than 5-6astronomical units (AU)) semi-major axes, a parameter-space impractical for the radial velocity technique since it requireslong baseline measurements patiently acquired over a significant fraction of one orbital period. For planets like Jupiter andSaturn, this time frame corresponds to 12 and 29 years, respectively. Derived from text

Astronomy; Planetary Systems; Surveys; Gemini Project; Planet Detection

20060000071 Gemini Observatory, Hilo, HI, USA

Recent Science Highlights

Roy, Jean-Rene; Fischer, Scott; Gemini Focus: Newsletter of the Gemini Observatory; December 2005, pp. 49-53; In English;See also 20060000060; Copyright; Avail.: Other Sources

Over 82 separate nights the Gemini North and Keck I telescopes mapped the clouds 0 of Saturn’s largest moon Titanduring a coordinated monitoring imaging campaign during the moon s 2003-2004 and 2004-2005 apparitions. Henry G. Roe(CalTech) and a team including Gemini s Chad Trujillo, found that Titan s recently discovered short-lived mid-latitudes cloudscluster near 350 degrees west longitude and 40 degrees south latitude. They can last as long as one Earth day beforedissipating. The observations point to a localized surface event such as geysering or cryovolcanism as a possible trigger forthe formation of these clouds. The team used adaptive optics systems on both Mauna Kea telescopes to map Titan s surfaceand atmospheric features at a spatial resolution of about 300 kilometers as shown in Figure 1 inset images. At Gemini North,the nightly monitoring of Titan with ALTAIR, (the facility adaptive optics system), was done as a test for multi-instrumentqueue observing, a mode that is now fully implemented. Derived from text

Titan Atmosphere; Dissipation; Infrared Telescopes; Spatial Resolution; Methane

Source: NASA