New Planets in Earth's Backyard
A NASA telescope makes the biggest planet discovery ever
TOP: NASA's Kepler space telescope
BOTTOM: Imagined view of the star Kepler-10 from the planet Kepler-10b, like the Sun rising over Earth.
(NASA / Wendy Stenzel / Kepler Mission / Dana Berry)
Astronomers have hit the planetary jackpot! NASA's Kepler space telescope has uncovered 1,235 potential exoplanets, or planets outside Earth's solar system. The discovery could triple the number of known planets.
Fifty-four of these exoplanets could potentially support human life. Like Earth, these planets orbit, or circle around, their stars at distances that allow temperatures to be warm enough for liquid water to exist on their surface. They are in what's called a habitable zone, or an area where living things might be able to survive.
Of the 54 planets in the habitable zone, five are approximately the size of Earth. The rest range in size from twice the size of Earth to larger than Jupiter—the largest planet in our solar system. Jupiter is 11 times the size of Earth.
Kepler also discovered six planets crowded around a star called Kepler-11. This family of potential planets is the largest group found orbiting a star outside our solar system.
SCANNING THE SKY
In March 2009, NASA launched Kepler into outer space to search for Earth-like planets in our galaxy, which is called the Milky Way.
The spacecraft has been orbiting the sun and scanning a part of the sky between two constellations, or groupings of stars, called Cygnus and Lyra. Using a tool that measures brightness, Kepler watches light from more than 156,000 stars and any planets that pass in front of them.
Still, Kepler monitors only about one four-hundredth of the sky.
"The fact that we've found so many planet candidates in such a tiny fraction of the sky suggests there are countless planets orbiting sunlike stars in our galaxy," said William Borucki of NASA's Ames Research Center in California.
Scientists plan to use other telescopes to confirm that these newly found objects are indeed planets.