Scientists find a planet in the "Goldilocks" zone - may contain life?

[Dumpy Dooby]

An Earthlike planet spotted outside our solar system is the first found that could support liquid water and harbor life, scientists announced Tuesday.

Liquid water is a key ingredient for life as we know it. The newfound planet is located at the "Goldilocks" distance — not too close and not too far from its star to keep water on its surface from freezing or vaporizing away.

And while astronomers are not yet able to look for signs of biology on the planet, the discovery is a milestone in planet detection and the search for extraterrestrial life, one with the potential to profoundly change our outlook on the universe.

”The goal is to find life on a planet like the earth around a star like the sun. This is a step in that direction,” said study leader Stephane Udry of the Geneva Observatory in Switzerland. “Each time you go one step forward you are very happy.”

The new planet is about 50 percent bigger than Earth and about five times more massive. The new “super-Earth” is called Gliese 581 C, after its star, Gliese 581, a diminutive red dwarf star located 20.5 light-years away that is about one-third as massive as the sun.

Smallest to date
Gliese 581 C is the smallest extrasolar planet, or “exoplanet,” discovered to date. It is located about 15 times closer to its star than Earth is to the sun; one year on the planet is equal to 13 Earth days. Because red dwarfs, also known as M dwarfs, are about 50 times dimmer than the sun and much cooler, their planets can orbit much closer to them while still remaining within their habitable zones, the spherical region around a star within which a planet’s temperature can sustain liquid water on its surface.

Because it lies within its star’s habitable zone and is relatively close to Earth, Gliese 581 C could be a very important target for future space missions dedicated to the search for extraterrestrial life, said study team member Xavier Delfosse of Grenoble University in France.

“On the treasure map of the universe, one would be tempted to mark this planet with an X,” Delfosse said.

Two other planets are known to inhabit the red dwarf system. One is a 15 Earth-mass “hot-Jupiter” gas planet discovered by the same team two years ago, which orbits even closer to its star than does Gliese 581 C. Another is an 8 Earth-mass planet discovered at the same time as Gliese 581 C, but which lies outside its star’s habitable zone.

Possible waterworld
Computer models predict Gliese 581 C is either a rocky planet like Earth or a waterworld covered entirely by oceans.

“We have estimated that the mean temperature of this super-Earth lies between 0 and 40 degrees Celsius [32 to 104 degrees Fahrenheit], and water would thus be liquid,” Udry said.

The scientists discovered the new world using the HARP instrument on the European Southern Observatory 3.6 meter telescope in La Sille, Chile. They employed the so-called radial velocity, or “wobble,” technique, in which the size and mass of a planet are determined based on small perturbations it induces in its parent star’s orbit via gravity.

Udry said there was a fair amount of time between the calculation of Gliese 581 C’s size and the realization it was within its star’s habitable zone. “That came at the end,” Udry said.

When it did hit him, Udry knew he would be spending time fielding phone calls from the media. “You right away think about the journalists who will like it very much,” he told Space.com.

More to come
David Charbonneau, an astronomer at the Harvard-Smithsonian Center for Astrophysics who was not involved in the study, said the new finding is an “absolutely fantastic discovery.”

“It means there probably are many more such planets out there,” Charbonneau said in a telephone interview. Whether Gliese 581 C harbors life is still unknown, but “it satisfies for the first time a key requirement.”

Charbonneau also praised the team’s technical skills. “The wobble induced on the star by each of these planets is really tiny — it’s just a few meters a second. That means their measurement precision is exquisite,” he said.

David Latham, another astronomer at Harvard-Smithsonian CfA, echoed other scientists’ praise of the discovery but said the next step is to find a similar world where the orbit of the habitable planet carries it between Earth and its parent star. This will allow scientists to observe it using the transit technique, whereby the small dimming starlight caused by the planet’s passage across the face of its sun can be used to calculate its size.

Only then can scientists determine for certain whether the world is rocky or covered by water, Latham said.

Alan Boss, a planetary theorist at the Carnegie Institution of Washington in Washington D.C., said the new planet’s potential for liquid water made it “fascinating." Gliese 581 C “is the closest planet to another Earth that has been found to date. I hope the SETI folks are listening,” Boss said.

Seth Shostak, a senior astronomer at the SETI institute, said the Gliese 581 system has in fact been looked at twice before for signs of intelligent life. The first time was in 1995 using the Parks Radio Telescope in Australia; the second time was using the Greenbank Radio Telescope in West Virgina. Both times revealed nothing.

“It has been looked at twice, but that doesn’t mean we shouldn’t look at it again,” Shostak said. “And indeed we should because this is the best candidate the solar planet guys have come up with yet.”

Shostak said he was “jazzed” by the discovery. “This is pointing to something that in the past has only been an assumption, namely that Earth-sized worlds are not rare,” he said. “We know of only two [planets in the habitable zone]. We know this one and we know our own. But two is better than one.”

Shostak said the Gliese 581 system might be looked at again when the new Allen Telescope Array begins operations this summer.

“You could say it’s going to the head of the class,” he said.


© 2007 Space.com. All rights reserved. More from Space.com.
URL: Scientists find most Earthlike planet yet - Space.com - MSNBC.com

[Linzyhop]

yeah, i read about this earlier today. Apparently bookies already started taking bets if there is alien life on it.

[Roonie]

I think this is really cool. I read about it oo. Scientists think temp somewhere between 32 and 104 F. Now if only we could figure out a way to get to it in our lifetime.

[Dumpy Dooby]

Originally Posted by Linzyhop

yeah, i read about this earlier today. Apparently bookies already started taking bets if there is alien life on it.

that's awesome.




I remember being a little kid and taking note of the fact that Earth's temperature falls within an amount that happens to coincide with the temperature at which water is ... well, water. At the time, it reinforced my belief in Jesus, but now I recognize it as an assured byproduct of our black-hole-generating universe. In any event, that's when I realized why there's not likely to be life out in the universe; the required temperature range is so incredibly precise. Personally, I think this discovery, regardless of whether or not it has life, is really quite remarkable.

[Nonphixion]

Holy shit! The Allen Telescope Array is actually going online?

Last I heard DARPA took over the reigns of this project years ago to use it for defense purposes. It would be great to see that it's going to be back in civil hands for civil purposes.

[Dumpy Dooby]

The thing that's funny, though, is this planet is circling a red dwarf. So even if they find life, it's likely not there anymore because its sun is probably dead by now.

[DosEquis]

Originally Posted by Dumpy Dooby

The thing that's funny, though, is this planet is circling a red dwarf. So even if they find life, it's likely not there anymore because its sun is probably dead by now.

Possibly. I am thinking when the star was in full force that it would be nearly impossible to support life because it would be way to hot given the distance from the planet to the star. Now that it is a red dwarf, that is what is making it possible for that temperature range.

SO assuming there is any water left and the planet didn't dry up a few billion years ago, it could be quite possible. Personally if i had to guess, i think it is just a giant rock with no water and very little atmosphere if any. It just happens to have a good temperature now.

I agree that the precise requirements that need to be there to support life makes a planet like ours extremely rare. There is simply to many solar systems and I think it would be a bit niave to dismiss all of them. Based on numbers alone there has to be another (if not many) planet some where with life on it. There are 30 billion-ish stars in our galaxy alone that are considered "sun-like". Not to mention it is rumored that there are over 100 billion galaxies of varying size.

[Dumpy Dooby]

Originally Posted by DosEquis

Possibly. I am thinking when the star was in full force that it would be nearly impossible to support life because it would be way to hot given the distance from the planet to the star. Now that it is a red dwarf, that is what is making it possible for that temperature range.

SO assuming there is any water left and the planet didn't dry up a few billion years ago, it could be quite possible. Personally if i had to guess, i think it is just a giant rock with no water and very little atmosphere if any. It just happens to have a good temperature now.

I agree that the precise requirements that need to be there to support life makes a planet like ours extremely rare. There is simply to many solar systems and I think it would be a bit niave to dismiss all of them. Based on numbers alone there has to be another (if not many) planet some where with life on it. There are 30 billion-ish stars in our galaxy alone that are considered "sun-like". Not to mention it is rumored that there are over 100 billion galaxies of varying size.

I liked redwards's post on :

Pure probability. The number of planets that there are estimated to be in the universe is something like 10^22. Billions upon billions upon billions.

We've already found a number which contain water. We've found two which contain water and have a nice temperate surface (we're sitting on one, the other was found a few days ago). If we can find 2 nicely suited planets out of the some 200-300 that we know of so far, and, of those, at least 50% have life (us), what are the chances that there are no other planets with life? Even if we assumed the chances were one in a billion, we'd have a hundred billion planets with life.

[mididoctors]

Originally Posted by Dumpy Dooby

I liked redwards's post on :

Pure probability. The number of planets that there are estimated to be in the universe is something like 10^22. Billions upon billions upon billions.

We've already found a number which contain water. We've found two which contain water and have a nice temperate surface (we're sitting on one, the other was found a few days ago). If we can find 2 nicely suited planets out of the some 200-300 that we know of so far, and, of those, at least 50% have life (us), what are the chances that there are no other planets with life? Even if we assumed the chances were one in a billion, we'd have a hundred billion planets with life.

the problem with 1 in a billion is that is still too vast a number to survey or find in a reasonable timeframe.. say we can survey/visit 1 solar system per day thats a billion days.. it would take 2 million yrs to find this other planet bearing life.. so either we up the survey rate (remotely) or listen for them(intelligence) to contact us or vice versa

the other issue is perhaps realizing how odd the earth is.. its not just the goldilocks zone that is an issue here...

we may have to face the idea that we are FUNCTIONALLY alone even if not actually alone

a alternative POV is that its early days for intelligent life on earth and we are the bacterial equivalent of intelligent civilizations as algae was to life on land... perhaps intelligent lfe on earth(or from earth) will last millions of years

Boris
Londdon