Sponsored by Delaware Asteroseismic Research Center at UD (www.physics.udel.edu/darc)
and Mount Cuba Astronomical Observatory (mountcuba.org)
2015 HARCOURT C. “ACE” VERNON MEMORIAL LECTURE
Wednesday, October 14, 2015 | 7:30 PM | Clayton Hall Conference Center
It’s astronomy’s biggest question. NASA’s Kepler space telescope, launched in 2009,
has found thousands of planets, some like Earth. Kepler scientist Fergal Mullally
will introduce you to how the spacecraft sleuths out planets, introduce some of
its most exciting discoveries, and discuss future missions that will help us
finally understand whether we are truly alone in the universe.
Kepler Science Officer,
The SETI Institute and
NASA Ames Research Center
Is Earth the only planet
in the universe that supports life?
This artist’s conception depicts the Kepler-10
star system, located about 560 light-years away.
Kepler-10b—to date, the smallest known planet
outside our solar system (dark spot against yellow sun)—
has a radius of 1.4 times that of Earth’s. In May 2010, the
Kepler team announced another member of the Kepler-10 family,
called Kepler-10c (larger foreground object). It’s bigger than Kepler-10b
with a radius of 2.2 times that of Earth’s, and it orbits the star every 45 days.
This chart compares the first Earth-size planets found around a sun-
like star to planets in our own solar system, Earth and Venus. NASA’s
Kepler mission discovered the newfound planets, called Kepler-20e
and Kepler-20f. Kepler-20e is slightly smaller than Venus with a radius
.87 times that of Earth. Kepler-20f is a bit larger than Earth at 1.03 times
the radius of Earth. Venus is very similar in size to Earth, with a radius
of .95 times that our planet. Prior to this discovery, the smallest known
planet orbiting a sun-like star was Kepler-10b with a radius of 1.42 that
of Earth, which translates to 2.9 times the volume.
Both Kepler-20e and Kepler-20f circle in close to their star, called
Kepler-20, with orbital periods of 6.1 and 19.6 days, respectively.
Astronomers say the two little planets are rocky like Earth but with
There are three other larger, likely gaseous planets also known to circle
the same star, known as Kepler-20b, Kepler-20c and Kepler-20d.