Friday, December 9, 2011

Via JMG: Closest Earth-Like Planet Yet Found

NASA reports:
It's the closest match to Earth that has yet been found. Recently discovered planet Kepler 22b has therefore instantly become the best place to find life outside our Solar System. The planet's host star, Kepler 22, is actually slightly smaller and cooler than the Sun, and lies 600 light-years from Earth toward the constellation of the Swan (Cygnus). The planet, Kepler 22b, is over twice the radius of the Earth and orbits slightly closer in, but lies in the habitable zone where liquid water could exist on the surface. Pictured above is an artist’s depiction of how Kepler 22b might appear to an approaching spaceship, in comparison to the inner planets of our Solar System. Whether Kepler 22b actually contains water or life is currently unknown. A SETI project, however, will begin monitoring Kepler 22b for signs of intelligence.
Start packing.

reposted from Joe


Daniel Clark Orey said...

repsoted JMG commente: As someone who works for one of the worlds largest optical/IR telescopes...

First, there have been direct observations of exoplanets (we do exoplanet discovery ourselves). However, at this point in time they resolve to a pixel (or less) on our sensors - so we can't image much.

The OP is correct in we make most of our discoveries based on periodic dips in the stars brightness. HOWEVER, telescopes coming online in the next 4 to 6 years will be able to directly observe the planets at much higher resolution (TMT is a good example - we are 8.2 meters, they will be 30 meter mirror).

Now... as per JOPA's reply of "I don't think anyone actually things there are telescope that can see 600 light years away? Surely?"...

Uh, jopa... 600 light years is VERY TINY in astronomical terms. And yes, we can see MUCH MUCH MUCH farther than that.

For example, the farthest object we have discovered was over 13 BILLION light years away... kinda puts your 600 light year comment to shame.

The difference is the SIZE of the structures we are looking at. A planet at 600 light years is so very very very tiny. A galaxy at 13 billion light years is still tiny, but lots more to image.

Daniel Clark Orey said...

reposted jmg comment 2:

The parallax method can go this distance nowadays. And the Gaia mission (lift-off 2013) will make distance measurements 100 times more precise from the previous best measurements (aside from Hubble etc which are even better). And from there you can use standard candles to climb the cosmic distance latter.

The distance of 190 pc/600 ly is not imagined, but measured. What NASA doesn't mention is the error bar in the distance measurement, which likely made you question the number. I can't even find it in the scientific paper

I'll make sure to look for a better number.

Daniel Clark Orey said...

JMG Comment 3:

Just for clarification on this point...
There is no center to the universe. There is no edge to the universe.
There is an OBSERVATIONAL EDGE for every point in the universe, relative to that point.
For example... we can see 13.7 billion light years in a sphere in all directions. We can't see past that point because light beyond that point has not had a chance to make it to us.
Every point in the universe has that 13.7 billion light year observational edge, from that points perspective.
If you were to move to a point 13.7 billion light years away (from us, so basically to our observational edge) you would still be able to see 13.7 billion light years in an observational sphere in all directions.

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