"Earths" in habitable zones common

[Waspie_Dwarf]

Earth-sized planets in habitable zones are more common than previously thought

UNIVERSITY PARK, Pa. -- The number of potentially habitable planets is greater than previously thought, according to a new analysis by a Penn State researcher, and some of those planets are likely lurking around nearby stars.

"We now estimate that if we were to look at 10 of the nearest small stars we would find about four potentially habitable planets, give or take," said Ravi Kopparapu, a post-doctoral researcher in geosciences. "That is a conservative estimate," he added. "There could be more."

Kopparapu detailed his findings in a paper accepted for publication in Astrophysical Journal Letters. In it, he recalculated the commonness of Earth-sized planets in the habitable zones of low-mass stars, also known as cool stars or M-dwarfs.

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Edited March 13, 2013 by Waspie_Dwarf

[spud the mackem]

We cannot be the only planet in the habitable zones, that has water,and a suitable atmosphere to support life,there has to be millions.

[bison]

The link to the article doesn't appear to be working.

[Waspie_Dwarf]

The link to the article doesn't appear to be working.

Thanks, it should be fixed now.

[bison]

Link now working, Thanks. Four habitable planets per ten M class stars, it says. That's about one for every 2.5 such stars. The three nearest such stars are Proxima Centauri, Barnard's star, and Wolf 359. One of these should, by this reckoning, have a habitable planet, and this, I read, is a conservative estimate.

[bison]

Proxima Centauri is thought to be about 4.85 billion years old, about 280 million years older than the Sun. Barnard's Star is estimated to be around 10 billion years old, over twice the Sun's age. Wolf 359 approximately 100- 300 million years old, very young by stellar standards. Either of the first two appear to have been around more than long enough to allow for the possibility of advanced, indigenous life. And all this within less than 8 light years.

Edited March 14, 2013 by bison

[Frank Merton]

Red dwarfs continue to present the two problems of frequent severe flaring and likely gravitational lock. This makes me question whether the presence of a "right" size planet or moon in the "habitable" zone of such stars means anything.

Of course if we can find them and identify them and get spectra, then we certainly should. Still, I am much more interested in the more difficult problem of finding earth-size objects around larger stars more like the sun. These of course will be less common but still numerous, although I am not aware of any studies predicting their liklihood.

[Artaxerxes]

I have read several near death experience descriptions where they came back and said that our universe is "alive with life." And other NDE descriptions that have said our Universe was "made for life." A few have even said that they met other beings on the other side who were not from our planet.

Art

[bison]

Red dwarfs continue to present the two problems of frequent severe flaring and likely gravitational lock. This makes me question whether the presence of a "right" size planet or moon in the "habitable" zone of such stars means anything.

Of course if we can find them and identify them and get spectra, then we certainly should. Still, I am much more interested in the more difficult problem of finding earth-size objects around larger stars more like the sun. These of course will be less common but still numerous, although I am not aware of any studies predicting their liklihood.

Red dwarf stars have only recently been seriously considered to host potentially habitable planets. There is a good deal we don't know about how tidally locked planets might distribute the heat they receive, or shield themselves from stellar variability. It used to be believed that most M class stars were not flare stars. Now that is reversed; most, but not all, are suspected of large, short term variability. As we refine our knowledge, it will become clearer if some planets of some M class stars are truly habitable, or not. Edited March 14, 2013 by bison