SANTA CRUZ, CA--A team of planet hunters led by astronomers at the University of California, Santa Cruz, and the Carnegie Institution of Washington has announced the discovery of an Earth-sized planet (three times the mass of Earth) orbiting a nearby star at a distance that places it squarely in the middle of the star's "habitable zone," where liquid water could exist on the planet's surface. If confirmed, this would be the most Earth-like exoplanet yet discovered and the first strong case for a potentially habitable one.One caution from the Bad Astronomer:
Gliese 581g, as the new planet is called, is in the zone where the temperature is just right. And with a mass of just three times that of the Earth, it’s unlikely to be a gas giant.That is true. But consider this: the Gliese 581 star system is 20 light years away from us. The Milky Way galaxy, our home, is 100,000 light years across and contains something on the order of 100 billion to 400+ billion stars. The number of star systems with planets in the "goldilocks zone" may be in the billions or tens of billions.
However, this does not mean the planet is habitable, or even very Earthlike. It may not even have any water on it at all. For now, we can’t know these things, so beware of any media breathlessly talking about life on this planet, or how we could live there.
The chances of there being planets out there with life forms would seem too be pretty good. Evolution would be at work there, as well. The likelihood of another planet developing one or more species that in turn develops artificial technology has to be something above zero.
I quite agree that there are in all probability many, many planets out there that have developed some form of life - given the numbers, it is a near certainty.
ReplyDeleteBut I don't think they've come to visit us, way out here on Podunk Earth, and likely never will.
Me life or no just the idea we can find a planet at that distance is interesting.
ReplyDeleteEck!