Added Siegfried Eggl, associate researcher at JPL: "Perhaps most surprisingly, our findings suggest that, under certain conditions, the presence of a giant planet can actually increase the size of the habitable zone, which is the area where your
terrestrial planet receives the right amount of light in order to support liquid water on its surface.
In other words, Vesta may be the preserved remnant of a transitional class of planetary objects--it's no longer a primitive asteroid but it's not quite a classical
terrestrial planet either.
"Our understanding is that this kind of meteorite is the starting composition of the
terrestrial planets, from Mercury to the Earth."
If water was plentiful in Earth's building blocks, many extrasolar
terrestrial planets could also have been born wet.
The discovery of the planet, dubbed COROT-Exo-7b, may ultimately provide groundbreaking information about the composition and structure of
terrestrial planets beyond the solar system.
New techniques, however, always are on the horizon, and a pair of upcoming space missions hope to detect a
terrestrial planet around another star: the Europeans are launching Corot in 2006 and NASA is unleashing Kepler in 2007.
Measuring the mass and radius of a
terrestrial planet reveals a planet's average density, and that in turn may indicate where the body formed.
"It could have been a former ocean world, or even [the core of] a former gas giant that evaporated, or a
terrestrial planet that was somehow pushed inward as an outer gas giant migrated inward," comments Brandon Tingley, a member of the CoRoT science team.
That may in turn be a sign of possible
terrestrial planet formation, Meyer and his colleagues, including Lynne Hillenbrand and John Carpenter of the California Institute of Technology in Pasadena, argue in the Feb.
In the hopes that a powerful "
Terrestrial Planet Finder" telescope will someday be launched, researchers have tested a way to detect the presence of oceans and clouds on Earth-like planets of far stars.
Other sections cover solar telescopes, wavefront sensing and control, mirror technology, NASA's
Terrestrial Planet Finder missions, and coronographs.
Papers on theory, attitude dynamics, attitude determination, orbit theory, and orbit and attitude theory describe recent work in areas such as nuclear electric sundiving, attitude estimation with GPS-like measurements, planet detection algorithms for the
terrestrial planet finder, and closed-form velocity solutions in lost-in-space attitude and position determination.