NASA says Kepler spacecraft proves it can find Earth-sized planets

Readings on the planet HAT-P-7b indicate that the craft's instruments should be able to spot relatively small planets in the habitable zones around stars in our galaxy, scientists say.
By John Johnson Jr.
August 7, 2009

NASA's planet-hunting spacecraft, Kepler, has made radical new discoveries about a hellish planet a thousand light years away -- proof, scientists say, that the craft will be able to carry out its mission of finding other Earths in our galaxy, provided they exist.

NASA scientists released Kepler's analysis Thursday of an already known "hot Jupiter" planet called HAT-P-7b in the constellation Cygnus. The spacecraft mapped the planet's orbit and gave new details about its hazy, ozone-like atmosphere, where temperatures climb as high as 5,000 degrees Fahrenheit.

The analysis proves that Kepler's onboard telescope and light-detecting instruments are at least 100 times more precise than the ground-based detectors that originally found HAT-P-7b, the scientists said at a briefing at NASA headquarters in Washington. That should be good enough to spot any pint-sized planets -- about the size of Earth -- in a star's so-called habitable zone, where temperatures are warm enough for water to be liquid but not so hot as to torch the planet's surface.

"Kepler has the ability to detect Earth-sized planets," Alan Boss, an astrophysicist with the Carnegie Institution of Washington, said at the briefing. "The question that remains is: How many Earths are there?"

Kepler, which was launched in March, is the first spacecraft with a mission to find potentially habitable worlds. Over the next few years, as it circles the sun in an Earth-trailing orbit, it will scan 100,000 stars in the constellations of Cygnus and Lyra, looking for planets.

more:

http://www.latimes.com/news/nationworld/nation/la-sci-kepler7-2009aug07,0,4825712.story

There are probably a lot of Earth sized planets within the habitable zone, but also probably very few to none with Earth-like conditions of liquid water and oxygen atmosphere.

http://en.wikipedia.org/wiki/Rare_Earth_hypothesis

With more than 100 billion galaxies (and trillions of stars with gravitational pulls) - many too far for humans to ever be able to see - it would stand to reason that you would find hundreds of thousands with Earth like conditions or close enough to produce intelligent life.

I stand more with Sagan than with Ward on this one.

For an Earthlike inhabitable world..

Plate tectonics (Venus is about the same size as Earth, has no tectonic activity), a large satellite (current theory implies the Moon was formed by an impact with the Earth), the right metallicity of the star in question and a host of other things.

On the other hand we really have zero idea whether Earthlike conditions are truly necessary for intelligent life to arise, there well could be intelligent life on other sorts of planets entirely that live by hitherto undreamed biologies.

Who was it that said that the universe is not only stranger than you imagine but stranger than you can imagine?

Edited to add another example..

There was a documentary about this not too long ago, very enlightening. Out of all the planets in our solar system, Earth is the ONLY one with a single large satellite. The diameter of the Moon is roughly 1/4 that of Earth's - no other moon in our solar system even comes close to that. Our moon is what keeps our planet from wobbling wildly on its axis, and helps keep our climate relatively stable.

And you're right about an impact forming the Moon. But not just any impact, but an impact from another Earth-sized planet impacting the Earth at a very precise angle. If the planet had hit Earth at a steeper angle, the two planets would likely have merged into one. At a lesser angle, then it might have simply careened off into space (obviously affecting Earth's orbit).

The more and more we learn about our planet, the more it appears to be quite a unique place. I'm sure that given the infinite number of planets throughout the universe, there are bound to be other planets almost identical to ours - but I'd guess that they are probably very few and far between.

Check it out if you've got a clear sky.

I was showing it to a couple of kids with my 6" Newtonian..

We thought we were seeing rings until those diamonds popped out with the binocs.