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Subscribe to RSSAstronomers say they've found the first planet beyond our solar system that could have the right size and setting to sustain life as we know it, only 20 light-years from Earth.
"My own personal feeling is that the chances of life on this planet are 100 percent," Steven Vogt, an astrophysicist at the University of California at Santa Cruz, told reporters today. "I have almost no doubt about it."
The discovery, published online in The Astrophysical Journal, is the result of 11 years of observations at the Keck Observatory in Hawaii. Astronomers participating in the Lick-Carnegie Exoplanet Survey detected the planet by tracking the faint gravitational wobbles it produced in its parent star. Now they say there may well be many more planets out there like this one.
"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," Vogt said in a news release.
One of Vogt's co-authors, Paul Butler of the Carnegie Institution, reminded reporters during a teleconference today that the first exoplanet orbiting a normal star was detected 15 years ago. Since then, almost 500 other alien planets have been found. "We're at exactly that threshold now with finding habitable planets," Butler said.
The newfound planet, known as Gliese 581g, is estimated to be 3.1 to 4.3 times as massive as Earth, and makes a complete circuit around its sun in just under 37 days. If the planet has a rocky composition like Earth's, it would be 1.2 to 1.4 times as wide as our own planet, qualifying it as a "super-Earth."
Even more intriguingly, the red dwarf star's dimness and the planet's orbital distance (0.146 AU, less than half the distance between Mercury and our sun) suggest that the planet's average surface temperature is not that far below water's freezing point (somewhere between 10 and -24 degrees Fahrenheit, or -12 and -31 degrees Celsius).
Although that average may sound chilly, the astronomers say Gliese 581g appears to be tidally locked to its star, with one side perpetually in the sun and the other side perpetually dark. That means the highs on the day side would be hellishly hot. The lows on the night side would be unendurably cold. But there would be a livable zone along the line between shadow and light.
"Any emerging life forms would have a wide range of stable climates to choose from and to evolve around, depending on their longitude," Vogt said.
Based on this analysis, Vogt and his colleagues say Gliese 581g is in a planetary zone that is, in the words of the Goldilocks tale, "not too hot and not too cold, but just right" for water to exist somewhere in liquid form. Astrobiologists say that life seems to exist anyplace on Earth that has liquid water, and that such a Goldilocks zone should be conducive to alien life as well. Some astronomers have even proposed that super-Earths could be friendlier to life than our own home world.
The Gliese 581 system is already well-known to planet hunters. Gliese 581g is the sixth planet to be detected around the parent star. Two other planets in the system are on the edges of the Goldilocks zone: Gliese 581c (potentially "too hot") and Gliese 581d (potentially "too cold"). "Now we have one in the middle that's just right," Vogt said.
The method that was used to detect the latest member of Gliese 581's planetary family, known as radial velocity, requires painstaking observations over a number of years. As the method is currently practiced, it's not capable of finding Earthlike planets around sunlike stars. The Lick-Carnegie Exoplanet Survey was able to spot this super-Earth because it could exert a relatively large pull on a relatively small star. But the observations weren't easy: It took 238 measurements, conducted over 11 years with the aid of the European-led HARPS team, to confirm Gliese 581g's existence.
Astronomers believe it will be easier in the future to find habitable planets — not only because they're building up a larger database of radial velocity measurements, but also because new space probes such as NASA's Kepler and Europe's CoRoT satellite are detecting hundreds of exoplanets using a different technique known as the transit method.
"The number of systems with potentially habitable planets is probably on the order of 10 or 20 percent, and when you multiply that by the hundreds of billions of stars in the Milky Way, that's a large number," Vogt said. "There could be tens of billions of these systems in our galaxy."
But how accessible would they be? Relatively speaking, Gliese 581g is in our celestial neighborhood, but it would take tens of thousands of years to get there using conventional rocket technologies. Vogt said it might be possible to send a robotic probe to the planet using an experimental nuclear propulsion system, such as the Project Orion system that was proposed a half-century ago but never built.
"If you're traveling at a tenth of the speed of light, you could reach this thing in 200 years," Vogt told reporters, "Now, you probably wouldn't send humans there, because that would be multiple generations and you'd need a big crew cabin and there wouldn't be much to do for 200 years. But you could send sophisticated robot cameras. Basically, the equivalent of a Droid cell phone would do pretty well. ... In 220 years, if we started now, you would be able to get close-up pictures and a sense of what kind of atmosphere was there, and radio communications, that sort of thing. And it would be a great thing to do with the world's stockpile of nuclear weapons. Just put 'em up on a rocket and send 'em up there."
More on alien planets:
- Too big? 55 Cancri appears to have a planet in the Goldilocks zone, but it's 45 times as massive as Earth. That's probably too massive for life as we know it, but life could conceivably exist on a moon (such as Pandora in the movie "Avatar").
- Too hot? As mentioned above, Gliese 581c might be on the edge of the Goldilocks zone, but astronomers are coming around to the view that it's too hot to sustain life. The planet is at least five times as massive as Earth.
- Too cold? When Gliese 581c fizzled, astronomers suggested that Gliese 581d might be on the other side of the star system's habitable zone. Astronomers say life could be a possibility if the planet had a thick atmosphere to hold onto heat. Otherwise, it's probably too cold. It's also seven times as massive as Earth.
- Planet theory: Four types of habitable planets proposed
- Countdown: Watch Keith Olbermann's chat with astronomer Derrick Pitts
- The world next door: Discovery suggests Mars was once habitable
- Millions of Earths? Astronomer's talk causes a stir
- More on the way: Hunt for new worlds goes into overdrive
- Looking for alien Earths? Probes could turn up hundreds
In addition to Vogt and Butler, authors of "The Lick-Carnegie Exoplanet Survey: A 3.1 Me Planet in the Habitable Zone of the Nearrby M3V Star Gliese 581" include Eugenio Rivera, Nader Haghighipour, Gregory W. Henry and Michael H. Williamson. The research was funded by the National Science Foundation, NASA and the Carnegie Institution. Watch NSF's webcast of today's news briefing on the discovery.
Join the Cosmic Log corps by signing up as my Facebook friend or hooking up via Twitter. And if you really want to be friendly, ask me about "The Case for Pluto."
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This is really funny. The theory of evolution is full of holes. Spontaneous life virtually impossible. Everyone who has bothered to look objectively at the theory gets this. Life would be elsewhere only if God decided to put it there, which would require the miraculous conditions, improbable beyond all odds, that permit us to live on this earth. I sincerely believe we're it. The universe exists as it does so that only a moron would observe it and deny God's majesty and creative genius.
Reading through a majority of the comments reminded me that there are some VERY strange people on this planet.
"...And it would be a great thing to do with the world's stockpile of nuclear weapons. Just put 'em up on a rocket and send 'em up there."
What? How about we send the nukes into a star; let's not pollute a virgin planet.
"...And it would be a great thing to do with the world's stockpile of nuclear weapons. Just put 'em up on a rocket and send 'em up there."
What? How about we send the nukes into a star and leave virgin planets alone.
I like when real news comes to my RSS folder.
As if man was in control, pathetic, they profess to be wise but the reality is they are fools. Alll they are doing is preparing an explanation so when millions of people worldwide DISSAPEAR in an event called the rapture, They will tell those left behind for the great tribulation that ALIENS came and took us and everything will be ok but it is a LIE. Time is short and mocking or scoffiing wont change a thing, in fact write this day and time down because it's around the corner.
Yes. " . . . nuclear weapons. Just put 'em up on a rocket and send 'em up there." along with 100% probability of life. I think we've hit an unprecedented level of egocentric arrogance. Perhaps, thank god armageddon is just around the corner.
By the time we're able to get there, we'll be lonnnnng extinct. One thing is for sure -- this will turn religion on its side. About time, too!
By the time we're able to get there, we'll be lonnnnng extinct. One thing is for sure -- this will turn religion on its side. About time, too!
How in the world will this turn religon on its side? God is the ultimate creator! Why would he create only one world!!!
NASA is going to have to figure out how to build a ship that can go faster than light. This suspense is killing me.
Just because there is a very remote "possibility" that the planet could support life doesn't mean that it actually does. And if it does, what could we expect to find there - single cell organisms? Complex life forms? Actual intelligence? Remember that we've only been able to send and receive radio waves for less than 100 years - a miniscule blip in time. It could be that they the planet will have single cell organisms in a billion years and will develop complex life in a few hundred million years after that - or they had intelligent life a billion years ago and has been a lifeless rock since then. The chances of discovering life on another planet that coincides with the brief 5 million years that humans have existed on planet Earth is very small indeed.
I really just can't understand why these astrophysicist pursue this. We already know there are no planets anywhere close to us. It would take tens or perhaps hundreds of years traveling at the speed of light to get to any of these planets. And if we've conquered the technology to live in space for that long, who would want to be stuck on a planet?
aren't you already stuck on a planet?
the comment that it would be a great thing to do with our nuclear stockpile is irresponsible!!!! We have to deal with our own problems not export them to another planet, particularly one that "may" contain life, either as we know it or otherwise.
Actually, the idea of sending the nukes up is to use them as propulsion. You build a ship with a HUGE, THICK dome on the back, like a rocket nozzle, pop a nuke out into the middle of it and detonate it, it provides thrust for the ship. The larger and heavier the ship is the smoother the thrust. Keep sending nukes out and you can get the craft up to a large percentage of light speed. When you reach the half way point, you turn the ship around and decelerate the same way. Look up the old Orion Project, not the newer one, but the old, 1950's version.
If its circling a Red sun, does that mean it's inhabitants will have super human strength and be able to fly if they came here?
Wishful thinking combined with a lack of evidence does not equal evidence (nor inevitability.) The more we find out about the increasingly large number of variables required for life to exist, the more it seems like someone has designed both life AND the environment of earth. Time and research are actually making a naturalistic theory (ie no god theory) even harder for a thinking person to hold to.
The more we study, the more Earth seems increasingly complex and designed.
We have two choices: Take care of our own planet or start chasing a dream in the stars. And by "take care of our own planet" I mean take care of our resources and learn to share them. We need a better way to control our population other than by war and disease. Sure, let's send a probe to a distant planet and learn all we can about it for future generations. But for those of us who live in the present, we need to figure out how to be better stewards of the Earth. I cannot do much, but at least I recycle.
Faster than light travel is not only possible, but closer than most would care to believe
"There could be tens of billions of these systems in our galaxy."
As you approach the center of the galaxy the background radiation increases. This would limit the amount of habitable planets for life as we know it in the Milky Way.
It's been awhile since I read up on these sort of things, but isn't this star a red dwarf? I seem to think I remember that our own sun would - in 5 billion years (give or take a decade) - become a red dwarf, thus expanding and in the process destroying the inner planets (Earth might either be consumed or if the sun didn't make it out this far, heat up the planet enough to boil away the oceans).
If the stellar life cycle is similar, why would it be thought that a planet that orbits a star every 37 days and is tidally locked to it, could possibly hold life? (I get the whole extremophile concept but this would be nothing more than a chunk of dead rock orbiting a dead star). It might be close to the right size, but I doubt this is the Earth Mark II that we're looking for.
Tony: Your thinking of a red giant. A red dwarf doesn't have the mass.
Doh! Like I said it has been awhile since I read up on these things. Thanks for the correction!
I find it horribly amusing that one of our "best and brightest" actually said: "And it would be a great thing to do with the world's stockpile of nuclear weapons. Just put 'em up on a rocket and send 'em up there."
So basically....polluting and trashing our own planet isn't good enough anymore....and what an excellent thing to do with a new planet that could potentially sustain human life. If sending our trash and waste to another planet is a considerable option, why would we ever send it to a planet with a possible future use? Why not dump that crap on Venus or Saturn for instance?
Humans are f-ing morons.
J, you may want to look at B. Honest's comment at #88.1
Interesting assumption considering the article says nothing about nuclear propulsion. The way I read the article was that it was 'suggested' that we could take our "stockpile of nuclear weapons" and just "send 'em up there" That sounds more like disposal to me and less like energy consumption.
J, this is taken directly from the article:
"Relatively speaking, Gliese 581g is in our celestial neighborhood, but it would take tens of thousands of years to get there using conventional rocket technologies. Vogt said it might be possible to send a robotic probe to the planet using an experimental nuclear propulsion system, such as the Project Orion system that was proposed a half-century ago but never built.
"If you're traveling at a tenth of the speed of light, you could reach this thing in 200 years," Vogt told reporters, "Now, you probably wouldn't send humans there, because that would be multiple generations and you'd need a big crew cabin and there wouldn't be much to do for 200 years. But you could send sophisticated robot cameras. Basically, the equivalent of a Droid cell phone would do pretty well. ... In 220 years, if we started now, you would be able to get close-up pictures and a sense of what kind of atmosphere was there, and radio communications, that sort of thing. And it would be a great thing to do with the world's stockpile of nuclear weapons. Just put 'em up on a rocket and send 'em up there.""
@ GBprime
I think that this is just another proof of just how rare life-supporting planets are. And how special. The circumstances have to be just right to support life. A little too much or not enough of something here or there will throw the whole thing off. Kinda makes you wonder why our planet is so special and how it overcame the incredible odds to get everything just right. Do you think it really all happened by chance? If so, it takes more faith to believe that, than faith to believe in an all powerful God that we could never come close to understanding. I hope that one day you would open your mind to the possiblity of God. I do believe that there could be life out there somewhere. But, if so, I firmly believe they were placed there by God.
Orbiting a red sun, Three times earth mass does this sound familar? I wonder how manny Kryptonians live there!
Wishful thinking combined with a lack of evidence does not equal evidence (nor inevitability.) The more we find out about the increasingly large number of variables required for life to exist, the more it seems like someone has designed both life AND the position of earth AND the environment of earth. Time and research are actually making a naturalistic theory (ie a "no god" theory) even harder for a thinking person to hold to.
The more we study, the more Earth and Life seem increasingly complex and designed.
GW11: If you actually looked at the paper, the article has the link to it, you would see they are talking about a habitable zone in which there could be liquid water. For organisms similiar to that on Earth, water is essential. There work is about trying to find planets with the possibilities of sustaining life as we know it. Next, correlating complexity with design is not a basis for God. If there was any intelligence involved objects and events would be much simpler. Complexity is messy, simplicity is eloquent. Whenever science and math come up with new formulas, they strive for simplicity, such as E=mc^2.
Wishful thinking combined with a lack of evidence does not equal evidence (nor inevitability.) The more we find out about the increasingly large number of variables required for life to exist, the more it seems like someone has designed both life AND the position of earth AND the environment of earth. Time and research are actually making a naturalistic theory (ie a "no god" theory) even harder for a thinking person to hold to.
The more we learn, the more Earth and Life seem increasingly complex and designed.
you mean we don't just exist because we just do? You just made quit a few atheist faint!!!
I didn't faint, but I did do a a face-palm. The more I learn, the less Earth and Life seem complex and designed.
Jsp- Please think about it some more. "How our planet overcame these odds"? It didn't overcome anything. It just happened. This is the anthropic principle. All the life that DIDN'T come to be on unsupporting planets did NOT get to ask the question. While it may be amazing that your particular number gets drawn in a lottery, it is not amazing at all that A number was drawn. And what you are in amazement about is that A number was drawn.
This is the anthropic principle. All the life that DIDN'T come to be on unsupporting planets did NOT get to ask the question. While it may be amazing that your particular number gets drawn in a lottery, it is not amazing at all that A number was drawn. And what you are in amazement about is that A number was drawn.
Yes but for life to exsist on any planet at all, it does not take one paticular thing to happen but thousands all at once! This is the fundimental flaw in the theory of self creation!!!!
We assume so because our only example for life is on Earth. The possibility of life not being carbon based exists, but we have absolutely no idea what that would look like, what range of parameters work for it, so on and so on and so on.
So until we stumble upon life that isn't like ours we search with what we know, and that is life that is like our own that requires conditions like ours.
If it is only 20 light years away, then SETI should have detected some electronically generated signals if there were any to detect. Therefore the life there is either not interested in long range commmunication or life there is very primitive.
Now as for how primitive, we need only scan our own prehistoric heritiage. Since everything feeds on something to sustain life, we might want to make sure what the native diet is before galavanting off beyond on own planet.