Space Journal Entry
Space Journal Entry
Kepler Finds New Exoplanets (March 15, 2010)
Artist's view of the Kepler spacecraft on its mission hunting for exoplanets. NASA.
In 2009, NASA launched the Kepler spacecraft on a mission to scan the skies for exoplanets, planets beyond the solar system. The space agency says Kepler recently spotted five new ones. All are hot gas giants in orbits close to their parent stars. The exoplanets were detected with the transit method by observing the tiny dip in light emitted by a parent star as the planet passes in front.
All five of the exoplanets orbit their stars in three to five Earth days. One is close in size to Neptune, while the other four are up to 50 percent larger than Jupiter. None resemble more Earth-like exoplanets such as GJ1214b and Corot-7b and none can support life. Still, their discovery raises hopes others will be found within a distant solar system's habitable zone, the region where it's neither too hot nor too cold for liquid water, and perhaps living things, to exist. Astronomers have detected more than 400 exoplanets so far.
The exoplanet called Kepler-7b is the most puzzling of the five. Although it's the largest, it's only 40 percent as massive as Jupiter. Its density is about one-sixth that of water or similar to that of Styrofoam. Astronomers aren't sure why it's so light but suspect some internal heat source might be puffing it up.
