Earth-Like Planet That Could Sustain Life Found

astroengine writes "An exoplanet, 20 to 50 percent the mass of Earth, has been discovered 20 light-years away and it appears to have all the ingredients conducive to sustaining life. It has enough gravitational clout to hold onto an atmosphere and it orbits well within the 'Goldilocks Zone' of its parent star. However, it would be a very different place to Earth; it is tidally locked to its star, creating one perpetual day on the world. Interestingly, this may also boost the life-giving qualities of the exoplanet, creating stable temperatures in its atmosphere."

Comments

Re:Annddd....

[The_mad_linguist]

His argument doesn't really hold water. Sure, once you have life that can survive on a planet it's a bitch to keep it away from anywhere, but there's no guarantee that you'll get that life to begin with.

Life (?)

[tanujt]

Just 20 light years away is good news! One thing that always bothers me when I read about E.T. life, is the fact that we get excited when we find water or an Earth-like atmosphere somewhere, thinking there should/might be life there. We should factor in the possibility that life may evolve entirely differently from us, without requiring water or nitrogen/oxygen. In that case though, we can't really know how it will have evolved as we have no reference of evolution other than ours. So let's wait, or just go there as soon as we can as aliens.

Re:why do stable chances increase the likelyhood?

[martin-boundary]

You'd be right only if evolution was merely a function of the environmental conditions. However, your algae and molds will also compete among themselves, leading to adaptation independently of the environment.

Re:why do stable chances increase the likelyhood?

[jrumney]

Look at where the most biodiverse regions are on Earth. They are in the equatorial zone, where the climate is stable.

Venus and Mars

[AJWM]

Venus and Mars are also rocky "Earthlike" planets orbiting roughly in the habzone ("goldilocks" zone).

I'd like to see truly terrestrial planets as much as (more than, probably) the next guy, but I think the reportage here is a bit hyped. Especially given a ~3x mass, that gives it roughly 1.44x the surface gravity (and higher likelihood of a Venus-like atmosphere).

Re:Venus and Mars

[Nadaka]

3 words words. Albedo, Greenhouse gasses.

The farther out you are, lower albedo and higher greenhouse gasses would be needed.

The closer in, higher albedo and lower greenhouse gasses would be needed.

Re:Alien astronomers

[geekoid]

50% either it does or it doesn't~

remember we are using 20 yr old data

[bl8n8r]

intriguing is the fact that we are studying the planet as it was 20 years ago, not as it is present day. In roughly 100 years we've managed to screw up this planet to no end. Things could be quite different on gliese 581g at this moment and we would not know it. Assuming we could travel at the speed of light and made it there in 20 years, the inhabitants may have already turned most of the planet to concrete and smog. If it is indeed inhabited.

Re:remember we are using 20 yr old data

[Anonymous Coward]

intriguing is the fact that we are studying the planet as it was 20 years ago, not as it is present day. In roughly 100 years we've managed to screw up this planet to no end. Things could be quite different on gliese 581g at this moment and we would not know it. Assuming we could travel at the speed of light and made it there in 20 years, the inhabitants may have already turned most of the planet to concrete and smog. If it is indeed inhabited.

It's intriguing to me that anyone would call cities "screwing up" the planet. We've transformed the environment into one that is incredibly comfortable for our species to live in. There has never been a better time. The real argument that we're screwing up the planet involves this state being unsustainable, not the fact that we've achieved it.

Re:remember we are using 20 yr old data

[Anonymous Coward]

The planet doesn't care, we don't matter. In ten thousand years most of what we'd done would be gone. In ten million years most every species alive now will be extinct humans or not. That's nothing in the lifetime of this planet. The natural state of things is change and right now we're little more than an amusing bump in the grand timeline of this planet.

Stop deluding yourself into thinking we matter or that there's some actual entity called "nature" that cares what you do.

In the end, the only reason nature or what we do matters is us and our future uses of it. No one else cares and even if we remove ourselves from existence in the most dramatic way possible there won't be much impact in ten million years.

Re:How can they tell its tidally locked?

[MaskedSlacker]

I don't know of any observational way to determine it at the distances involved (though there may be one), but if you make certain assumptions about the composition of the planet you can determine the maximum amount of time it takes to become tidally locked (basically, all orbiting bodies become tidally locked eventually, it's just a question of how long), and if that time is less than the time we can estimate the planet to have existed we can conclude that it SHOULD be tidally locked.

See also: http://en.wikipedia.org/wiki/Tidal_locking#Timescale

Re:Only 20 light years???

[mangu]

20 light years is millimeters of astrophysical distance.

It amazes me we have been observing space so long and yet we only now have detected this planet.

This just goes to show you the difference in difficulty between finding a Jupiter-sized planet and an Earth-sized planet.

Wow

[MyLongNickName]

My what exciting times we live in. Just think... it has only been around 100 years since we realized the universe is organized into galaxies. Only a few hundred since we realized that the Earth is not the center of the universe. Sometimes it is hard to have faith in the future... but discoveries like this touch that small part of me that hasn't become jaded.

Re:Only 20 light years???

[Penguinisto]

And while 20 light years might be small by astronomical standards, human beings haven't even been two light *seconds* away from the earth.

FWIW, Voyager 1 is about 14-15 light-hours away now.

Something to consider, though - not all radiation is the evil, hazardous, cancer-causing flesh-melting variety. Light is radiation, which is, well what they'd been using to study this thing. The shallow end of the details pool can be had here(pdf).

Also, they're not just blindly poking around at random bits of cubic space - they're starting with stars, eh?

Re:Annddd....

[SETIGuy]

This is where I stopped reading:

That's a very appropriate point to stop. To paraphrase Clarke: "When a senior scientist tells you something is impossible, they are likely to be wrong. When a senior scientist tells you something is certain, they are likely to be wrong. When a senior scientist tells you something may be possible, they are probably correct."

to put 20 light years in perspective...

[physicsdot]

20 light years is *about* 1.25 million AU. Voyager is 113 AU from the sun, in under 4 years it will be 125 AU from the sun. If we pretended Voyager 1 was heading the in right direction it would be 1/10000 of the way there. Or if we imagined that the planet was 10 meters away, Voyager has travelled 1mm of the way there. About 350000 AD, it would arrive!

Re:Summary is wrong.

[phlegmofdiscontent]

Space.com gives a better summary:

http://www.space.com/scienceastronomy/earth-like-exoplanet-possibly-habitable-100929.html

However, I think the 20% to 50% number comes from the size of the star, Gliese 581. The mass of the star is 20% to 50% of the sun's mass.

Thus far, the lowest-massed planet discovered by the radial velocity method was about 150% to 200% the mass of Earth. Discovering one as small as 20% to 50% is currently beyond the capabilities of the RV method, so the 300% to 400% figure makes a lot more sense.

Re:Only 20 light years???

[IICV]

Something to consider, though - not all radiation is the evil, hazardous, cancer-causing flesh-melting variety. Light is radiation, which is, well what they'd been using to study this thing.

The GP poster neither said nor implied anything along those lines, and indeed was clearly using the "light is radiation" definition (among other ones, of course - it's not like our telescopes are limited to the visible spectrum any more). Has Slashdot fallen so low that we actually need to randomly defend the usage of the word "radiation"? I thought most of the people here had a reasonable understanding of science.

Re:Annddd....

[Anonymous Brave Guy]

I'd say it doesn't hold water because... well, he simply doesn't have enough information at this point.

Indeed. From the Bad Astronomy blog:

However, this does not mean the planet is habitable, or even very Earthlike. It may not even have any water on it at all. For now, we can't know these things, so beware of any media breathlessly talking about life on this planet, or how we could live there.