Right Thinking From The Left Coast
Adventure is worthwhile - Aesop

Friday, February 04, 2011

Planets Planets Everywhere

So a little mental health break.  An awesome mental health break.

[The Kepler satellite] detects planets by looking for the tell-tale dip in light as they pass in front of their star, and the amount of light blocked tells us the size of the planet. Kepler is staring at one part of the sky, continuously looking at 156,000 stars for these dips. After 23 months in orbit, it now has a passel of 1235 candidate planets. Of these, 68 are roughly Earth-sized, 288 are bigger than Earth, 662 are roughly Neptune-sized, 165 are Jupiter-like, and 19 are larger than Jupiter.

Five of the Earth-sized planets are in the habitable zone—the region where liquid water could exist.  That doesn’t mean it does; it means it could.

Five Earth-like planets may not sound like much, but keep some things in mind.  Kepler is only surveying 156,000 of the nearly 400 billion stars in our Galaxy.  Kepler can only detect planets if their orbit happens to place them between the star and Earth—a very narrow viewing angle.  So for every planet you detect, there is a sea of those you can’t because their orbits aren’t aligned the right way.  Finally, Kepler has only been up for two years, so planets with longer orbits have not been seen yet.

If you extrapolate that out, that would mean there are many millions of Earth-like planets in our Galaxy, even being very generous with the uncertainties.  That’s not even including moons that could be orbiting the so-called “hot Jupiters”—giant planets that are within the habitable zone that may themselves be uninhabitable but sport habitable moons (think Endor or Yavin).  There are about 50 habitable zone giant planets such detected by Kepler.

The diversity of planetary systems is incredible—one has five planets inside the orbit of Mercury.  When I started out in astronomy, it was taken for granted that other solar systems would be like our own (based on a sample of ... well ... one).  We’ve now found out this isn’t anywhere close to true.  The planetary systems show in Star Wars and Firefly were more realistic than our old theories.  Such is the case when you get data in place of theory.

So is there life out there?  I find it amazingly likely that there is ... somewhere.  Hell, there might be life right within our own solar system, in the ices of Mars or the oceans of Europa.  Intelligent life?  Well, we can hope.  It always bears reminding that intelligent life has only been around on Earth for a tiny amount of time.  We’ve been broadcasting messages into space for about 75 years—only one hundred millionth of the time Earth has been around.  If we destroyed ourselves tomorrow—always a possibility with the Confederacy of Dicksmacks currently in Washington—and our duration was typical of intelligent life, there might be only one other civilization in the entire Galaxy.  And it might take tens of thousands of years for us to hear what they have to say.

I’m an optimist, however.  I think it’s only a matter of time until we find some evidence that we’re not alone.  My personal theory is that there is intelligent life out there.  They’re just encasing us in silence to prevent the spread of Keynesian economics.

Posted by Hal_10000 on 02/04/11 at 06:29 PM in Science and Technology  • (0) TrackbacksPermalink
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