# First rocky exoplanet that could host life



## rcapo89

The new planet is called Gliese 581 g. 

http://www.newscientist.com/article...exoplanet-that-could-host-life.html?full=true

http://www.telegraph.co.uk/science/...xist-on-Earth-like-planet-scientists-say.html



> Astronomers have found the first alien world that could support life on its surface. It is both at the right distance from its star to potentially harbour liquid water and probably has a rocky composition like Earth.
> 
> "That's the most exciting exoplanet I've seen yet," says James Kasting of Pennsylvania State University in University Park, who was not involved in the discovery.
> 
> The planet orbits a dim red dwarf star 20 light years from Earth called Gliese 581. Four planets were already known around the star, with two lying near the inner and outer edges of the habitable zone, where liquid water - and therefore potentially life - could exist on its surface.
> 
> One of those, which travels on a 13-day orbit, seems too hot for liquid water. The other, on a 67-day orbit, may be just warm enough for liquid water, but its status is not completely settled, says Kasting. Opinions "may continue to swing back and forth because it is hovering right near the outer edge", he says.
> 
> The newly found "Goldilocks" planet, called Gliese 581 g, lies in between the hot and cold ones. "You're smack dab in the middle of the habitable zone, so that's perfect," says Kasting, who has studied the two planets on the zone's edges.
> 
> Steven Vogt of the University of California, Santa Cruz, and Paul Butler of the Carnegie Institution of Washington, DC, used the 10-metre Keck I telescope in Hawaii to measure the wobbles of the parent star in response to gravitational tugs from its planets. They combined their data with measurements published by Michel Mayor of Geneva Observatory and his colleagues using a 3.6-metre telescope at the European Southern Observatory in Chile.
> 
> *Rocky super-Earth*
> 
> The wobbles revealed two previously undiscovered planets around the star, for a total of six. One is about seven times the mass of Earth and in a 433-day orbit - much too far from its star to support liquid water.
> 
> The other, Gliese 581 g, lies in the habitable zone and has a 37-day orbit. Its mass is between 3.1 and 4.3 times that of Earth.
> 
> Its relatively low mass means it should be made mostly of rock, like Earth. Simulations show that planets that grow beyond about 10 Earth masses collect a lot of gas, becoming uninhabitable giants like Jupiter, with no solid or liquid surface to provide a toehold for life.
> 
> Some giant planets have previously been found in the habitable zones around their stars, but have generated less excitement because of their inhospitable structure.
> 
> *Twilight zone*
> 
> Conditions on the planet would be very different from those on Earth. The host star is a low-mass red dwarf that is just 1 per cent as bright as the sun.
> 
> Because it puts out so little light and warmth, its habitable zone lies much closer in than does the sun's. At such tight distances, planets in the zone experience strong gravitational tugs from the star that probably slow their rotation over time, until they become "locked" with one side always facing the star, just as the moon always keeps the same face pointed towards Earth.
> 
> That would mean perpetual daylight on one side of the planet and permanent shadow on the other. A first approximation suggests the temperature would be 71 °C on the day side and -34 °C on the night side, though winds could soften the differences by redistributing heat around the planet.
> 
> Travelling from one side of the planet to the other, there would be a range of intermediate temperatures, says Vogt. "The most comfortable place on this planet &#8230; is along what we call the terminator, the line between light and dark," he says. "You basically see the star sitting on the horizon - you see an eternal sunrise or sunset."
> 
> *First of many*
> 
> The discovery suggests habitable planets must be common, with 10 to 20 per cent of red dwarfs and sun-like stars boasting them, the team says. That's because Gliese 581 is one of just nine stars out to its distance that have been searched with high enough precision to reveal a planet in the habitable zone.
> 
> "If you take the number of stars in our galaxy - a few hundred billion - and multiply them by 10 or 20 per cent, you end up with 20 or 40 billion potentially habitable planets out there," says Vogt. "It's a very large number."
> 
> Although the new planet is in the habitable zone, we are unlikely to find out whether it is actually inhabited anytime soon. One way to find out would be to measure the planet's light spectrum, which could reveal molecular oxygen or other possible signs of life in its atmosphere. But the overwhelming glare from its parent star makes it impossible to do that with current instruments.
> 
> *Vital signs*
> 
> However, Butler says this is probably just the first of many rocky planets likely to be found in the habitable zone in the coming years, and some of these are likely to be much more amenable to follow-up observations.
> 
> They include habitable planets that happen to pass in front of, or transit, their parent stars as seen from Earth. That alignment makes it much easier to measure light from their atmospheres, a feat that might be done with future ground-based telescopes with 25- to 40-metre mirrors, Butler says. Others have calculated that NASA's James Webb Space Telescope, to launch in 2014, could pull off the same feat for the very closest solar systems.
> 
> "While we won't probe this [planet's] atmosphere, there will be a habitable planet whose atmosphere we can probe sometime in this decade," Butler says.
> 
> The discovery comes on the heels of a recent attempt to predict when the first habitable Earth-like planet would be found. That study suggested it would happen in the first half of 2011, and most likely in May.


----------



## coldsorehighlighter

I read about this. Pretty cool stuff. I don't think that anyone currently alive will still be alive on the day where we find that intelligent life exists outside of this galaxy, but it's interesting anyways.


----------



## Keith

Really cool stuff


----------



## Neptunus

"Exoplanet," that's a new term for me. Very cool, though.


----------



## Jnmcda0

In regards to the percentage of stars in the Milky Way that have planets in the habitable zone, it seems like an enormous amount of speculation given the small data pool we have so far. Until we examine more stars and find more planets, I wouldn't put too much stock in the estimates.

I had posted in another thread about Gleise 581 d possibly being in the habitable zone. It's cool they've found another that planet in the system that is definitely in the range. Personally, I think they should have named the star Omicron Persei and named the new planet Omicron Persei 8.


----------



## OrbitalResonance

Neptunus said:


> "Exoplanet," that's a new term for me. Very cool, though.


 Its the term for all planets outside the solarsystem. Extra Solar Planet. Its newer term. Short.


----------



## Neptunus

^ Yeah, I gathered that from the context, but thanks.


----------



## shyvr6

I wonder if the aliens there will want us to come to their planet, lol? If it can support life, then there is a chance for an intelligent species. Hopefully, there wouldn't be, but the real problem is getting there.


----------



## OrbitalResonance

Here is a size comparison between earth and Gliese 581c which is a neighbor to Gliese 581 G. C is 5x the mass of earth and G is 3X the mass, so G would be somewhat inbetween the two.

 

Image Copyright Walter Myers
Earth and Gliese 581 c compared


----------



## DyingInTheOutside

This is very interesting stuff, I have a feeling I'll be glued to my computer trying to find out everything that the astrologists know from now until 2012... errrr I mean when I die....


----------



## OrbitalResonance

Heres an information paragraph i forgot to post for the pic in the last post.


> Gliese 581 c is believed to be about five times more massive than the Earth with a diameter about half-again as large as Earth's. Depending upon the planet's composition, whether mostly rock or a combination of rock a water, a visitor would experience a surface gravity between 1.25 to 2.2 times the Earth's. Gliese 581 c is about 20 light years away, a "next door neighbor" in stellar terms, but far beyond the reach of human visitors with today's technology.
> This image of a rocky and variegated Gliese 581 c with an atmosphere and clouds is purely speculative.


Here is another picture of it.

 



> In April 2007 the Geneva Observatory in Switzerland announced the discovery of a "super-earth" extrasolar planet orbiting the red dwarf star Gliese 581. Dubbed _Gliese 581 c_, it's been called a super-earth because it is one of the few known extrasolar planets that has a mass near Earth's, and the only one to occupy its sun's "habitable zone."
> This image of a rocky and variegated Gliese 581 c with an atmosphere and clouds is purely speculative.


Note, Gliese 581C is believed to be in the green zone as well, depending on the atmosphere.

Speculation of the surface.
 


> There is special interest in Gliese 581 c because it is the only known extrasolar planet where liquid water--a necessary ingredient for life as we know it--could exist. Surface temperatures are believed to range between the freezing point of water to about 100° F. However, there are other factors that could affect these values, including the possibility that Gliese 581 c always keeps the same side facing its host star, with the result that one side would become extremely hot while the other extremely cold.
> In this image from the surface of Gliese 581 c, its red dwarf host hangs low in the sky over a rocky and watery terrain. This sun has a diameter and radius about a third that of the earth's sun's and it is only about 1/100th as bright. It appears large in the sky because Gliese 581 c orbits relatively close to this red dwarf, completing an orbit in only 14 days.


More Speculation on C.
 


> The potentially earth-like extrasolar planet Gliese 581 c orbits very close to its red dwarf sun, completing an orbit in only 14 days. This planet experiences tidal forces about 400 times as strong as those that the Moon causes on the Earth, with the result that it may be tidally locked to the star with one hemisphere always day and the other always night. The sunward side would be extremely hot and the dark side extremely cold, while the narrow terminator or "twilight zone" between them might have a moderate climate possibly suitable for life.
> In this image, the temperate surface at the terminator of Gliese 581 c is host to liquid water and a variety of living plants. Two smaller moons occupy the sky, though there's no evidence yet that this planet hosts any moons of its own.


Really Neat



> Flying life forms grace the crimson skies of the potentially earth-like extrasolar planet Gliese 581 c. The red dwarf star Gliese 581 rests on the horizon, presiding over a liquid water sea. Eclipsing the red dwarf is Gliese 581 b, a sister planet in the same system with a mass 17 times that of the Earth. While the existence of all three bodies has been confirmed, it is not known if Gliese 581 c has all the necessary ingredients to support life as we know it.


----------



## Neptunus

^ Beautiful pics!


----------



## DyingInTheOutside

Amazing pictures, even if it's all speculation, kudos to the person who put those photos together


----------



## papaSmurf

Oh man, I read about this earlier in the week. So exciting! The best part is that they're only going to find more and more of these in the next few years.


----------



## CeilingStarer

Things like this actually perk me up a lot from my depressive state. It's like we're back hundreds of years again, when explorers were finding exotic shores. 

There's this feeling that the US government is about to give disclosure or something of late. Every week, there seems to be more stuff in the news concerning planets and life, an increase in UFO sightings (Chinese airport etc), astrophysicists speculating on alien life ... all at a time when NASA only recently upgraded their deep space telescope, and all the Zecharia Sitchen/Von Daniiken re-visitation type stuff is meant to come in to play. It's probably just a big snowball of hype/over-excitement/pseudoscience, but it certainly gets me interested in the coming decade. 

Even if my personal life remains bleak, there will possibly be some cool **** going on at least.


----------



## OrbitalResonance

CeilingStarer said:


> Things like this actually perk me up a lot from my depressive state. It's like we're back hundreds of years again, when explorers were finding exotic shores.
> 
> There's this feeling that the US government is about to give disclosure or something of late. Every week, there seems to be more stuff in the news concerning planets and life, an increase in UFO sightings (Chinese airport etc), astrophysicists speculating on alien life ... all at a time when NASA only recently upgraded their deep space telescope, and all the Zecharia Sitchen/Von Daniiken re-visitation type stuff is meant to come in to play. It's probably just a big snowball of hype/over-excitement/pseudoscience, but it certainly gets me interested in the coming decade.
> 
> Even if my personal life remains bleak, there will possibly be some cool **** going on at least.


We are starting to get good at this exoplanet stuff! Things will contimue to ramp up!


----------



## OrbitalResonance




----------



## Jnmcda0

A Swiss observatory said that they were not able to confirm the data that was presented by the observatory that first reported the findings, casting doubt on whether this planet exists.

http://www.space.com/scienceastronomy/doubt-cast-habitable-alien-planet-gliese-581g-101012.html


----------



## hellofromthegutter

Jnmcda0 said:


> Personally, I think they should have named the star Omicron Persei and named the new planet Omicron Persei 8.


LOL! i agree completely


----------



## leonardess

fantastic. I have a few exes I'd like to send there. of course, you're talking about a planet that can host _life_.....


----------



## mindsanitizer

you mean the first planet humans on earth found out about... i'm sure there are many planets out there in this vast space that can host/have life.

human technology cannot go that far from earth... lest say 100 lights year is covering all space.... humans can only go to the moon! not even a light year. their radio waves can only go out hmmm...forget how far but is not that far. this may put things in perspective http://science.howstuffworks.com/dictionary/astronomy-terms/question94.htm/printable

so i'm to believe that earth's the only planet that holds life... burp!!


----------

