Are you interested in Earth-like exoplanets?  If so, Kepler is for you.  The mission was designed to continuously monitor around 145,000 main sequence stars at a time, watching for periodic dips in brightness that indicate a planet in transiting.  Transiting is when the planet passes across your line of sight to the star in its orbit.  It blocks a bit of the star’s light, causing a tiny, tiny dip in brightness which can be detected and analyzed.  Based on information obtained studying the star as the planet transits, scientists can tell a lot about the planet.

NASA/Ames/JPL-CalTech

Kepler is able to zero in on Earth-sized planets, which will dip the parent star’s apparent magnitude by 0.01%.  So far, Kepler has found 68 Earth-sized planetary candidates, and 54 candidates in the parent star’s habitable zone.  Because of Kepler’s information, scientists estimate that 6% of all stars have Earth-like candidates.

Artists conception of red dwarf star Gliese 581 - NASA/ESO

Six percent.  If that doesn’t light your fire, I don’t know what to tell you.  Let’s pretend there are only one million stars in the Milky Way Galaxy.  We know there are lot more than a million, but let’s stick with that number for now.  Okay, one million stars.  Six percent of those are Earth-like candidates.  That would mean there are 60,000 possible Earths out there.  Now, the real Milky Way Galaxy contains between 200 and 400 BILLION stars.  The numbers starting to gang up on you?

Isn’t that exciting?  Doesn’t that flip your switch?

Working on it! Kepler's first five planets -- NASA/ESA/JPL/David Koch, Alan Gould, Edna DeVore

Kepler is not in orbit around the Earth; it trails the Earth in its orbit around the Sun.  That way, the Earth doesn’t get in the way of the stars Kepler is viewing.  It was launched from Cape Canaveral in Florida March 7, 2009.  It was successfully placed in orbit and popped its cover April 7, 2009.  Kepler’s first light images were taken the next day.

Painting by Jon Lomberg/NASA

Kepler downloads bout 90 to 100 gigabits of data per month.  Remember your computer science terms; a gigabit (Gbit) is 10(9) bits, or 1,000,000,000 bits.  A byte is 8 bits, and 1 Gbit is equal to 125 megabytes.  A couple of months of that would blow your laptop right out of the water.

You can join Kepler, by the way, and link your computer into the hunt for exoplanets.  Don’t worry, they won’t blast your laptop into the ozone.  The information they give you is modified for your computer.  The site will set you up and show you how to hunt for planets, and you, yes YOU!, can discover an exoplanet.

Zooniverse Home – I dare you!

Kepler Scientific Webpage

Discovery News – Exoplanet Bonanza