EARTH-LIKE? One of two newly discovered exoplanets is nearly the size of Earth and resides in a habitable zone around its star, raising the possibility of liquid water, the stuff of life as we know it.
Image: ESO
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A team of astronomers announced they have discovered the smallest and potentially most Earth-like extrasolar planet yet. Five times as massive as Earth, it orbits a relatively cool star at a distance that would provide earthly temperatures as well, signaling the possibility of liquid water.
"The separation between the planet and its star is just right for having liquid water at its surface," says astronomer and team spokesperson Stephane Udry of the Observatory of Geneva in Versoix, Switzerland. "That's why we are a bit excited."
But researchers do not yet know if the planet contains water, if it is truly rocky like Earth, which might make it hospitable to life as we know it, or whether it is blanketed by a thick atmosphere. "What we have," Udry says, "is the minimum mass of the planet and its separation" from its star.
The researchers say they detected the presence of two new extrasolar planets (exoplanets) around a red dwarf star, Gliese 581, 20.5 light-years away in the constellation Libra, based on slight motions of the star. Their discovery brings the total number of planets orbiting Gliese 581 to three; two years ago they made the initial finding of a planet there.
Udry says the group has submitted a paper for peer review and plans to publish a draft this week. "The claim is extremely interesting and the team is very credible," says astronomer David Charbonneau of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., adding that he cannot judge the validity of the claim until the team publishes its data.
Researchers believe that many smallish exoplanets exist, but so far they have only found 13 "super Earths" weighing in at less than 20 Earth masses, compared with more than 200 heavier gaseous planets. Udry's group searches for smaller planets using a telescope called HARPS (High Accuracy Radial velocity Planet Searcher), which looks for stars that wobble slightly.
As a planet orbits, it pulls a star back and forth. The range of motion increases with the planet's mass, and the time needed for one orbit (or one back and forth) translates into its distance from the star.
The smaller of the new planets, dubbed Gliese 581 c, orbits at one fourteenth the distance between Earth and the sun. But the red dwarf is 50 times cooler than the sun. The group estimates that the planet would experience temperatures in the zero-to-40-degree-Celsius (32-to-104-Fahrenheit) range.
"It's sort of at the 'Goldilocks' distance," says Charbonneau—closer to its star and the heat would vaporize any water; farther away and water would freeze.
The big question is whether there really is water on Gliese 581 c's surface, which requires that its surface be solid. Udry says planets smaller than 15 Earth masses are likely to be rocky or icy.
Charbonneau is more cautious. A five-Earth-mass planet "sort of looks like Earth, but it sort of looks like Neptune. So which is it?" he says. "There's just no way to know."
Prior Water Claim Evaporated?
In related news, a recent report of water vapor on gaseous extrasolar planet HD 209458 b may have been premature. Earlier this month, an astronomer claimed as much based on measurements of starlight passing through the planet's atmosphere.
Charbonneau, who led the team that collected the data, says the analysis is unconvincing because the telescope itself may have introduced variation that could be mistaken for fluctuation in light coming from the star.
Observations by the Hubble or Spitzer space telescopes may resolve the question once and for all in coming months, Charbonneau says.
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21 Comments
Add Commentand a planet has to have water to support life because? just how sure are we that there are no entities that don't need water?
Reply | Report Abuse | Link to thisand water is required because? just how sure are we that there are no entities that don't need water?
Reply | Report Abuse | Link to thisGreat find! now lets occupy it without religon, televangelist and politicans...
Reply | Report Abuse | Link to thisNO WONDER BECAUSE IT WAS ALREADY PROVED FROM SOME SCIENTIFIC CORNER THAT THE LIFE IN THE EARTH CAME FROM SPACE-PANSPERMIA
Reply | Report Abuse | Link to thisNo wonder because it was already proved from some scientific corner that the life from the earth came from space. Please refer Panspermia. Some times it will be the origin of another earth.
Reply | Report Abuse | Link to thisRavi
Well, "oldbat" if there is liquid water on a planet similar to ours, the chance exists that they may have evolved similarly. It is more interesting for us to find an entity that is made of the same stuff as us. For instance, if life was silicon-based on the planet, there would not be the same type of living bodies, and it is most likely that water is the basis of life being a breathing, thinking organisms. We're looking for "life as we know it."
Reply | Report Abuse | Link to thisA new Earth has been found - Gliese 581 c
Reply | Report Abuse | Link to thisAstronomers have found the most Earth-like planet outside our Solar System to date, a world which could have water running on its surface. The temperature of this 'super-Earth' lies between 0 and 40 degrees Celsius, and water would thus be liquid. The planet orbits the faint star Gliese 581, which is 20.5 light-years away in the constellation Libra. It is about 50 percent bigger than Earth and about five times more massive.
The newfound planet is located at the "Goldilocks" distance-not too close and not too far from its star to keep water on its surface from freezing or vaporizing away.
Scientists made the discovery using the Eso 3.6 m Telescope in Chile.
The temperatures on the planet mean any water there could exist in liquid form, and this raises the chances it could also harbor life. Its radius should be only 1.5 times the Earth's radius, and models predict that the planet should be either rocky - like our Earth - or covered with oceans.
The explanted - as astronomers call planets around a star other than the Sun - is the smallest yet found, and has been given the designation Gliese 581 c. It completes a full orbit of its parent star in just 13 days. Indeed, it is 14 times closer to its star than the Earth is to our Sun.
However, given that the host star is smaller and colder than the Sun - and thus less luminous - the planet nevertheless lies in the "habitable zone", the region around a star where water could be liquid.
Gliese 581 c was identified at the European Southern Observatory (Eso) facility at La Silla in the Atacama Desert.
To make their discovery, researchers used a very sensitive instrument that can measure tiny changes in the velocity of a star as it experiences the gravitational tug of a nearby planet.
Astronomers are not yet able to look for signs of biology on the planet, the discovery is a milestone in planet detection and the search for extraterrestrial life.
The Gliese 581 system has now yielded three planets: the new super-Earth, a 15 Earth-mass planet (Gliese 581 b) orbiting even closer to the parent star, and an eight Earth-mass planet that lies further out (Gliese 581 d).
exo planet maybe the soul planet that may the spirit of a person go and live forever.. . . . .
Reply | Report Abuse | Link to thisYou people astound me with your lack of knowledge of basic chemistry. "oldbat" seems to think that the entities need water to drink.
Reply | Report Abuse | Link to thisNO NO NO!!
Water is required for Carbon to form the complex chains that are necessary in order for life as we know it to exist. Without water, very few, if any, Organic chemical reactions are possible.
A better question, and what you were probably wanting to say, is "what if life exists there based on another element- say, Silicon?" Well, you still need water to form the compounds that create cells and DNA and so forth, but at least if you had said THAT I wouldn't have berated you.
How can you people subscribe to Scientific American and have such a lack of knowledge of basic chemistry? No one expects you to be able to derive the equation for calculating pH, but geez, Carbon compounds being the basis for life is freakin' HIGH SCHOOL chemistry.
Another thing, even if there are reactions that can occur using Si that could possibly result in a form of life without water, then by definition, that would NOT be "life as we know it." It would be something else- and then you'd have to get into the philosophical ramifications of how we define life, and I'm npt going to do that here.
If you want to discuss science, please have at least an elementary knowledge of it first.
Peace!
Courtney
Sorry for my abrasive post yesterday.
Reply | Report Abuse | Link to thisIf you will allow me to indulge you, rather than cast frustrated insults...
Not everyone is expected to know this, I'm sorry, I was just shocked at how many people have replied to all these "exoplanet" posts throughout the science feeds (not just on this page) and none of them seemed to have this knowledge which is elementary to the science of Organic Chemistry.
If a scientist were this ignorant of say, Dickens' "A Tale of Two Cities", or looked at you cluelessly if you quoted the phrase: "To be or not to be- that is the question..." you would know doubt think he was an idiot.
Now you guys see why the majority of the world thinks we Americans are idiots. I would bet dollars to navy beans that everyone who has posted in this forum above is an American, and I know that because your educations are one-sided. This is NOT to say any of you are stupid; quite the contrary, if you were actually stupid, I wouldn't berate you as I have, I'd just feel bad for you. It's because all your posts (even the ones about the souls of the dead living on Aldebaran or wherever- perhaps even especially those) show a great deal of intellectual curiosity and ability that I become so frustrated at the lack of scientific education in the American scholastic sytstem. It is not just High Schools that are at fault- colleges are even worse, if possible. If I am a liberal arts major at my local state school, I can graduate without taking a single science class, except for Biology, which, IMHO, should NOT count. Neither should Freshman astronomy, you know, that astronomy course that they give to non-science majors so they can get an applied science credit. Neither intro biology or intro astronomy are REAL science, yet the state seems to think that's all the science a student needs to wield a college degree.
And we wonder why our economy is failing, particularly since our economy is almost ENTIRELY a technology-based system. Without research to discover new tech, it can't grow, and it WON'T grow if everyone is ignorant of science, cuz ignorant adults raise ignorant kids who think science is "hard" and won't major in it. Ten years down the road, then, there's no new scientists, no new research, therefore the USA cannot compete in today's market. Q.E.D.
I'm not a scientist by trade-I'm a musician, but I think my level of education in science ought to be a bare MINIMUM for an educated human being in the 21st century. History and lit are just as important, but not MORE so!
Courtney Patricia "GuitarNGamerGirl" Parso
Well congrats to Courtney, you've Single-handedly managed keep this discussion page dead for a month. Don't be intimidated people! You make good solid points, however you contradict your own argument. Most Americans lack basic knowledge pertaining to chem and science but that doesn't mean that people shouldn’t subscribe to something that can enrich and better their knowlege of it. Anyone can whip out their old school books
Reply | Report Abuse | Link to thisWell congrats to Courtney, you've Single-handedly managed keep this discussion page dead for a month. Don't be intimidated people! You make good solid points, however you contradict your own argument. Most Americans lack basic knowledge pertaining to chem and science but that doesn't mean that people shouldn’t subscribe to something that can enrich and better their knowlege of it. Anyone can whip out their old school books and verbally degrade, the question is what will you do to change the system?
Reply | Report Abuse | Link to thisWell congrats to Courtney, you've Single-handedly managed keep this discussion page dead for a month. Don't be intimidated people! You make good solid points, however you contradict your own argument. Most Americans lack basic knowledge pertaining to chem and science but that doesn't mean that people shouldn’t subscribe to something that can enrich and better their knowledge of it. Anyone can whip out their old school books and verbally degrade, the question is what will you do to fix the system?
Reply | Report Abuse | Link to thisthe greater question is where does this woman get off on blasting the very education system that gave her the very disposition to knowledge she has? I do not disagree that the American school system has its faults, but its far better receive a "limited education", as she would call it, than none at all, like the 6 billion other persons in the world.
Reply | Report Abuse | Link to thisFinally, why do the majority of these communications suppose that if life exists outside of Earth, that it must reflect life on Earth in its formation? That is the real and only question we should discuss. We as humans wish this to be the case inherently so that the life we discover, if discovered, is something we can relate to, and would obviously facilitate our understanding. The aforementioned comments, and the continued discussions of "life as we know it" reflect a commonly held viewpoint/wish. Is the boogy-man of completely dissimilar life that horrific, or out of the question?
Maybe 'oldbat' was referring to ammonia, formamide, hydrogen fluoride methanol, uranium hexafluoride, hydrogen sulfide, hydrogen chloride or methane/ethane as possible solvents to spawn life. For all we know live can even thrive in plasma or polymeric atoms in neutron stars.
Reply | Report Abuse | Link to thislife*
Reply | Report Abuse | Link to thisis it possible that we are living infact the entire universe including all the galaxies we see,all the stars millions and millions of light years away are in side the body of one entity and then there are many entities like them
Reply | Report Abuse | Link to thisFor example inside human being body there are many bones and cells that make one human being so maybe we are inside the body of some entity
I`m wondering about exoplanets... and an idea came while I was reading! What is going to be the planet's name? Who will be the Choosen One to name the planet...we're reaching the a completely new age in the life as we know it... I think that the planet has to be named after Galileo Galilei ... he was who begun!!!
Reply | Report Abuse | Link to thisEven thought u find a new planet
Reply | Report Abuse | Link to thisCan u go there?? :))
I know ,huh.
Reply | Report Abuse | Link to thisI am defending oldbat here in the unprovoked attack from the musical physicist..Oldbat didnt say life as we know it, he said entity which could be carbon, silicon or something we are not even capable of classifying which may be even more interesting then anything as we know it...Im sure the critic is interested in wind instruments because she spent a lot of time blowing her own horn.
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