Earth-Sized planet in Habitable Zone

[Alg]

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

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").

[The_Gabe]

Neat

[Skeptical]

They've been predicting life on other planets ever since people realized that they were out there.

 

It would be interesting to see what the theists would say if we did find life on another planet.

[Bows]

That's actually pretty cool. :thumbup:

[Zygimantas]

They've been predicting life on other planets ever since people realized that they were out there.

 

It would be interesting to see what the theists would say if we did find life on another planet.

They would say that god did it.

[fakeitormakeit2]

They've been predicting life on other planets ever since people realized that they were out there.

 

It would be interesting to see what the theists would say if we did find life on another planet.

That it was predictable because mathematically it is almost impossible that we have the only planet inhabited in all of the universe, seeing as how we live on one planet out of seven [sic] planets in our star system, which there are 100 billion star systems in our galaxy and there are more than 100 billion galaxies. I don't see what theism, a metaphysical subject, has to do with alien life form discovery, a physical subject. Some people on this forum just try to inflame tension. You might be surprised to know not all people who believe in God think the earth is 6000yrs old, evolution is a lie and we are the center of the universe. Still yet, some heathens amongst us, dare I say a majority, believe in the sinful Big Bang Theory (except that's not even all that radical, seeing as how a Roman Catholic priest proposed the initial hypothesis).

 

By the way, why do they theorize that liquid water is a necessity of alien existence on a planet? Wouldn't it be possible that other living creatures could have another sustaining substance with their bodies being comprised of different compounds or would that be a stretch to say?

[blakdragon39]

By the way, why do they theorize that liquid water is a necessity of alien existence on a planet? Wouldn't it be possible that other living creatures could have another sustaining substance with their bodies being comprised of different compounds or would that be a stretch to say?

 

I think that's totally valid. It's something I've always wondered as well. :P

[Guest Rob]

Single-Cell life forms have to develop in something, are there any other elements (that we know of) that can do that?

[sees_all1]

They've been predicting life on other planets ever since people realized that they were out there.

 

It would be interesting to see what the theists would say if we did find life on another planet.

 

Maybe you should search "Roman Catholic church aliens" - you'll be surprised what you find.

[Giordano]

They've been predicting life on other planets ever since people realized that they were out there.

 

It would be interesting to see what the theists would say if we did find life on another planet.

 

Maybe you should search "Roman Catholic church aliens" - you'll be surprised what you find.

Every Saint was an alien, including Jesus.

 

God is the name of their Mothership. True story.

[Alg]

Every Saint was an alien, including Jesus.

 

God is the name of their Mothership. True story.

That's actually the same point made by one of those History channel programs, so you're now in the same class as the DaVinci code's secrets.

:twisted:

[Shiny]

I think this is pretty cool. I wonder how they will find out if there is indeed life on it? How many light-years is the star away from us?

[The_Gabe]

I think this is pretty cool. I wonder how they will find out if there is indeed life on it? How many light-years is the star away from us?

 

20

[tripsis]

Haha I attend UCSC so I got an e-mail about this today :lol: Here's the campus press release if you guys are interested. Probably contains about the same information as the article in the first post though.

[Nenga]

They've been predicting life on other planets ever since people realized that they were out there.

 

It would be interesting to see what the theists would say if we did find life on another planet.

That it was predictable because mathematically it is almost impossible that we have the only planet inhabited in all of the universe, seeing as how we live on one planet out of seven [sic] planets in our star system, which there are 100 billion star systems in our galaxy and there are more than 100 billion galaxies. I don't see what theism, a metaphysical subject, has to do with alien life form discovery, a physical subject. Some people on this forum just try to inflame tension. You might be surprised to know not all people who believe in God think the earth is 6000yrs old, evolution is a lie and we are the center of the universe. Still yet, some heathens amongst us, dare I say a majority, believe in the sinful Big Bang Theory (except that's not even all that radical, seeing as how a Roman Catholic priest proposed the initial hypothesis).

 

By the way, why do they theorize that liquid water is a necessity of alien existence on a planet? Wouldn't it be possible that other living creatures could have another sustaining substance with their bodies being comprised of different compounds or would that be a stretch to say?

It's creationism. That we are made in gods image, and the discovery of aliens would debunk that some to people. Though most likely they would just say god did that as well. It's much easier to slap a broad label on something than answer a question.

[Zygimantas]

They've been predicting life on other planets ever since people realized that they were out there.

 

It would be interesting to see what the theists would say if we did find life on another planet.

That it was predictable because mathematically it is almost impossible that we have the only planet inhabited in all of the universe, seeing as how we live on one planet out of seven [sic] planets in our star system, which there are 100 billion star systems in our galaxy and there are more than 100 billion galaxies. I don't see what theism, a metaphysical subject, has to do with alien life form discovery, a physical subject. Some people on this forum just try to inflame tension. You might be surprised to know not all people who believe in God think the earth is 6000yrs old, evolution is a lie and we are the center of the universe. Still yet, some heathens amongst us, dare I say a majority, believe in the sinful Big Bang Theory (except that's not even all that radical, seeing as how a Roman Catholic priest proposed the initial hypothesis).

 

By the way, why do they theorize that liquid water is a necessity of alien existence on a planet? Wouldn't it be possible that other living creatures could have another sustaining substance with their bodies being comprised of different compounds or would that be a stretch to say?

It's creationism. That we are made in gods image, and the discovery of aliens would debunk that some to people. Though most likely they would just say god did that as well. It's much easier to slap a broad label on something than answer a question.

Mhm. Because how can something happen without god influencing it right?

A group of students in my study hall ( they weren't that bright) were trying to answer the question: "What came first, the chicken or the egg?" It then quickly turned into, what did god make first? They didn't really use any science in their argument and their conclusion was that: "We don't know if god created the chicken or the egg first." They were looking at the question all wrong :lol:

[Will H]

 

By the way, why do they theorize that liquid water is a necessity of alien existence on a planet? Wouldn't it be possible that other living creatures could have another sustaining substance with their bodies being comprised of different compounds or would that be a stretch to say?

 

That's a mighty good question. Scientists tend to look for water when they're looking for life because they're simply going with what they know. There might be another set of 'building blocks' of life that don't include water, which act in a completely different way to how our 'building blocks' interact, but we'd be looking for a really specific set of certain needles in a really huge haystack filled with needles. We may as well start off looking for a planet like our own, because we know for certain that water, amino acids and oxygen, a gravitational factor of about 10g, and temperature of about 20C has harboured life: us.

[Skeptical]

I agree with Will.

 

If we're going to look for other life, then looking for planets with water is a good way to start.

[Bier]

By the way, why do they theorize that liquid water is a necessity of alien existence on a planet? Wouldn't it be possible that other living creatures could have another sustaining substance with their bodies being comprised of different compounds or would that be a stretch to say?

 

I think that's totally valid. It's something I've always wondered as well. :P

There's currently no theory to describe live without water, however that doesn't mean that it isn't possible.

 

I think this is pretty cool. I wonder how they will find out if there is indeed life on it? How many light-years is the star away from us?

If they find find oxygen in the planets atmosphere there's definitely life on the planet since only life can release oxygen as fast as it is bound by the planet. If no oxygen is found there could still be live, the first life on earth didn't produce any oxygen.

[blakdragon39]

If they find find oxygen in the planets atmosphere there's definitely life on the planet since only life can release oxygen as fast as it is bound by the planet. If no oxygen is found there could still be live, the first life on earth didn't produce any oxygen.

 

I don't think the presence of oxygen proves the presence of life at all... There could be a PLANET made of oxygen for all we know, with no life on it. I don't think any of the science we know about our planet or solar system can be applied flawlessly to other planets/solar system. Things could be very, very different, and until we can travel outside of our solar system, we'll never know.

[Zierro]

We have no idea. We could be all alone for all we know. There's no evidence for extraterrestrials, only a huge gap of knowledge.

[Star_Fox]

Isn't this old news? I remember reading about Gilese 581 somewhere...:|

[obfuscator]

They've been predicting this kind of thing for a while, but there are several problems that come up right away - such as gravity and extreme temperature. I'll be more exciting once they find something we could practically live on.

 

Not to mention the 87000 year journey there.

[Alg]

They've been predicting this kind of thing for a while, but there are several problems that come up right away - such as gravity and extreme temperature. I'll be more exciting once they find something we could practically live on.

 

Not to mention the 87000 year journey there.

Baby steps! :razz:

[sohkmj1]

They've been predicting this kind of thing for a while, but there are several problems that come up right away - such as gravity and extreme temperature. I'll be more exciting once they find something we could practically live on.

 

Not to mention the 87000 year journey there.

I'm sure they'll have a solution to that by the time they figure out if there is life on the planet or not (both statements).