Earth-like planet discovered

[hepcat]

I think we'll actually find a new planet to move to someday.

NASA and NSF-Funded Research Finds First Potentially Habitable Exoplanet09.29.10 The planetary orbits of the Gliese 581 system compared to those of our own solar system. Image Credit: National Science Foundation.

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This artist's conception shows the inner four planets of the Gliese 581 system and their host star. Image Credit: Lynette Cook.

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A team of planet hunters from the University of California (UC) Santa Cruz, and the Carnegie Institution of Washington has announced the discovery of a planet with 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."

This discovery was the result of more than a decade of observations using the W. M. Keck Observatory in Hawaii, one of the world's largest optical telescopes. The research, sponsored by NASA and the National Science Foundation, placed the planet in an area 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.

To astronomers, a "potentially habitable" planet is one that could sustain life, not necessarily one where humans would thrive. Habitability depends on many factors, but having liquid water and an atmosphere are among the most important.

The new findings are based on 11 years of observations of the nearby red dwarf star Gliese 581using the HIRES spectrometer on the Keck I Telescope. The spectrometer allows precise measurements of a star's radial velocity (its motion along the line of sight from Earth), which can reveal the presence of planets. The gravitational tug of an orbiting planet causes periodic changes in the radial velocity of the host star. Multiple planets induce complex wobbles in the star's motion, and astronomers use sophisticated analyses to detect planets and determine their orbits and masses.

"Keck's long-term observations of the wobble of nearby stars enabled the detection of this multi-planetary system," said Mario R. Perez, Keck program scientist at NASA Headquarters in Washington. "Keck is once again proving itself an amazing tool for scientific research."

Steven Vogt, professor of astronomy and astrophysics at UC Santa Cruz, and Paul Butler of the Carnegie Institution lead the Lick-Carnegie Exoplanet Survey. The team's new findings are reported in a paper published in the Astrophysical Journal and posted online at:

http://arxiv.org

"Our findings offer a very compelling case for a potentially habitable planet," said Vogt. "The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common."

The paper reports the discovery of two new planets around Gliese 581. This brings the total number of known planets around this star to six, the most yet discovered in a planetary system outside of our own. Like our solar system, the planets around Gliese 581 have nearly-circular orbits.

The new planet designated Gliese 581g has a mass three to four times that of Earth and orbits its star in just under 37 days. Its mass indicates that it is probably a rocky planet with a definite surface and enough gravity to hold on to an atmosphere.

Gliese 581, located 20 light years away from Earth in the constellation Libra, has two previously detected planets that lie at the edges of the habitable zone, one on the hot side (planet c) and one on the cold side (planet d). While some astronomers still think planet d may be habitable if it has a thick atmosphere with a strong greenhouse effect to warm it up, others are skeptical. The newly-discovered planet g, however, lies right in the middle of the habitable zone.

The planet is tidally locked to the star, meaning that one side is always facing the star and basking in perpetual daylight, while the side facing away from the star is in perpetual darkness. One effect of this is to stabilize the planet's surface climates, according to Vogt. The most habitable zone on the planet's surface would be the line between shadow and light (known as the "terminator").

http://www.nasa.gov/topics/universe/features/gliese_581_feature.html

More info here:

http://en.wikipedia.org/wiki/Gliese_581_g

[Delhommey]

Living in constant twilight makes for an interesting artistic premise.

[Squirrel]

To astronomers, a "potentially habitable" planet is one that could sustain life, not necessarily one where humans would thrive. Habitability depends on many factors, but having liquid water and an atmosphere are among the most important.

Really? They had to point this out.

[Darth Biscuit]

I think that this stuff is cool as hell... and to think they've only been studying a very tiny fraction of space and already found something like this. There's GOT to be other earth like planets in our galaxy.

[mmmbeans]

Living in constant twilight makes for an interesting artistic premise.

There are a couple of Heavy Metal stories that have dealt with the idea.

[hepcat]

I think that this stuff is cool as hell... and to think they've only been studying a very tiny fraction of space and already found something like this. There's GOT to be other earth like planets in our galaxy.

Sure is promising...if we don't anhiliate ourselves. We're pretty dumb. A few more centuries of mind/thought evolution should help. I mean we haven't even figured out how to live on our own planet yet...we'd just f*ck the next one up even worse at this point.

[Doyle]

I think it's only 20 light years away so we could go there someday.

[Hawk]

apparently the rams are already considering building a stadium there

[g5jamz]

take about 10,000 years to get there....but yeah.

Let's get working on that warp drive.

[hepcat]

I think it's only 20 light years away so we could go there someday.

Or at least send SOMETHING there. We wouldn't send generations of humans there if we weren't absolutely SURE we could live there...or wait I take that back. We might.

[Zod]

Sure, science says all that. Yeah right. buncha loonies libs.

[Darth Biscuit]

Or at least send SOMETHING there. We wouldn't send generations of humans there if we weren't absolutely SURE we could live there...or wait I take that back. We might.

Yeah, as neat as it is to find something like this, I think there are better candidates than this one... sounds like it has a pretty small area of habitability. I bet they find more and better planets in the next couple of years.

Problem is, unless there is some major, major breakthrough in propulsion engineering, we aren't seeing another planet like this anytime soon. 20 years at light speed and we can't even get up to a fraction of light speed now...

[Guest]

[Doyle]

We can get Earnhardt Jr. to pilot the ship. We will get there in no time.