A NASA illustration comparing the newly discovered planets to Venus and Earth. Kepler-20e is slightly smaller than both Venus and Earth. Kepler-20f is slightly larger.
SETI says that its Allen Telescope Array will be back online in September, thanks to funding secured from online donations. The array is seen here, adjacent to a cow pasture in Hat Creek, Calif.
Astronaut Steve Bowen works outside the International Space Station's Quest airlock during Monday's spacewalk. Bowen's spacewalk was unexpectedly extended by a computer malfunction.