|Six worlds orbit Kepler-11,
a sunlike star 2,000 light-years
distant in the constellation Cygnus.
The new discovery, based on data from NASA's
planet hunting Kepler spacecraft,
makes the Kepler-11 system
the fullest exoplanetary system known.
Compared to our Solar System in this illustration,
five of Kepler-11's planets orbit closer to their parent star than the
Mercury-Sun distance, with
orbital periods ranging from 10 to 47 days.
All six are larger than Earth and are likely composed of mixtures of
rocky material and gas.
Their presence, sizes, and masses have been determined by carefully
watching the planets dim the light of Kepler-11 while
crossing in front of the star itself.
In fact, in August 2010, Kepler's telescope and camera
recorded a simultaneous transit of three of the planets in the system.
As announced yesterday,
using the transit technique
the Kepler mission has now identified over
1200 exoplanet candidates in a
field of view
that covers only about 1/400th of the sky.
The tantalizing result suggests there are many
planets orbiting the stars in
Tim Pyle, NASA