National Aeronautics and Space Administration (NASA) announced on Friday that its Kepler telescope has discovered 11 new planetary systems that include 26 confirmed alien planets. The new planets vary in size from one-and-a-half times the radius of Earth to bigger than Jupiter. Their orbital periods range from six to 143 days, and they all orbit closer to their stars than Venus does to our sun. The discoveries nearly double the number of alien worlds — or “exoplanets” planets — found by Kepler outside our solar system and help astronomers better understand how planets form. However, scientists still have to determine the make-up of the planets, such as whether their surfaces are rocky or gaseous. “Prior to the Kepler mission, we knew of perhaps 500 exoplanets across the whole sky,” Doug Hudgins, Kepler program scientist at NASA Headquarters in Washington, said in a statement. “Now, in just two years staring at a patch of sky not much bigger than your fist, Kepler has discovered more than 60 planets and more than 2,300 planet candidates. This tells us that our galaxy is positively loaded with planets of all sizes and orbits.”
Kepler is NASA's first mission in search of Earth-like planets orbiting stars similar to our Sun. It launched in March 2009, equipped with the largest camera ever sent into space -- a 95-megapixel array of charge-coupled devices -- and is expected to continue its science operations until at least November 2012. In December last year, NASA announced Kepler had confirmed its first-ever planet in a habitable zone outside our solar system, Kepler 22b, though it remained unclear whether the surface was rocky or gaseous. Such planets have the right distance from their star to support water, plus a suitable temperature and atmosphere to support life. Spinning around its star some 600 light years away, Kepler 22b is 2.4 times the size of the Earth and orbits its Sun-like star every 290 days.
