Re:'Second Earth' found, 20 light years away
by DanielBMarkham on Tuesday October 16, 2007 @07:49PM
(#68817)
That's what I thought.
Although the discovery is amazing, there's a bit of over-selling in the article. It's a detection based on a wiggle that means the model says there's a world where the model says it would be mostly rocky where the model says....
I guess I can stop painting those "Welcome E.T." signs now.
I didn't explain myself properly. The planet is almost certainly there.
The atmosphere, color, etc.. of the planet is still in the speculation stage.
Re:'Second Earth' found, 20 light years away
by DanielBMarkham on Tuesday October 16, 2007 @08:38PM
(#68840)
I understood what you meant. The wobble prediction method is a lot more mature than various models of planetary formation. And the planet cannot be directly observed, only properties about it inferred from the wobble. No spectral measurements of the planet or its atmosphere were made.
It'll be great when we can start making direct observations instead of doing a lot of inference.
The planet was found by repeatedly observing the same star over and over, and measuring how fast the star is moving away or towards us. This wiggle is produced by the motion of planets. It's really small. Currently the best team (full disclosure: one of my advisors is on it) can measure velocities of 30 centimeter per second. Pause and reflect. It's an amazingly difficult and important detection.