Munich, April 24: An international team of astronomers from Switzerland, France and Portugal have discovered the most Earth-like planet outside our Solar System to date. Posted on 04/24/2007 1:41:01 PM PDT by Sopater
Munich, April 24: An international team of astronomers from Switzerland, France and Portugal have discovered the most Earth-like planet outside our Solar System to date.
The planet has a radius only 50 percent larger than Earth and is very likely to contain liquid water on its surface.
The research team used the European Southern Observatory’s (ESO’s) 3.6-m telescope to discover the super-Earth, which has a mass about five times that of the Earth and orbits a red dwarf already known to harbour a Neptune-mass planet.
Astronomers believe there is a strong possibility in the presence of a third planet with a mass about eight times that of the Earth in the system.
However, unlike our Earth, this planet takes only 13 days to complete one orbit round its star. It is also 14 times closer to its star than the Earth is from the Sun.
However, since its host star, the red dwarf Gliese 581, is smaller and colder than the Sun – and thus less luminous – the planet lies in the habitable zone, the region around a star where water could be liquid!
“We have estimated that the mean temperature of this super-Earth lies between 0 and 40 degrees Celsius, and water would thus be liquid,” said Stéphane Udry from the Geneva Observatory, Switzerland and lead-author of the paper in the journal Astronomy and Astrophysics.
“Moreover, 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,” he said.
“Liquid water is critical to life as we know it and because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extra-terrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X,” added Xavier Delfosse, a member of the team from Grenoble University, France.
According to the research team, the host star, Gliese 581, is among the 100 closest stars to us, located only 20.5 light-years away in the constellation Libra (“the Scales”).
The star has a mass only one third that of the Sun. Such red dwarfs are at least 50 times intrinsically fainter than the Sun and are the most common stars in our Galaxy. Among the 100 closest stars to the Sun, 80 belong to this class.
“Red dwarfs are ideal targets for the search for such planets because they emit less light, and the habitable zone is thus much closer to them than it is around the Sun. Any planets that lie in this zone are more easily detected with the radial-velocity method, the most successful in detecting exoplanets,” said Xavier Bonfils, a co-worker from Lisbon University.
Bureau Report
No the libs can stay here.. The real people can leave this frakin rock....
Very, very cool. Sure, habitable might be a stretch, but apart from Mars, it’s looking like our next best bet. Which obviously isn’t saying much, but still.
Really neat!
The angular momentum(AM) of a planet is derived from the AM of the whole system at it’s formation. If it’s too great, the system won’t form, and the greater it is, the longer it takes to form. So there’s an upper limit to the spin of the whole system from the beginning. The planets usually end up round. That wouldn’t happen, if there was a significant centrifical force at the equator. It would be an oblate spheroid. That pic does look like the equitorial radius might be ~17% greater than the polar radius though. That’s if it’s a pic of the planet and it’s not been distorted by a pic edit. In that case, the gravitational force at the surface would be would be 1.8, instead of 2.2.
1.5 times the diameter. 5 times the mass. Thus putting you at about 60 pounds :)
2.2(1-0.17)=1.8
Depending on the pic...
Great story. Gliese 581c is going to surprise us someday, I suspect.
Sooner or later, thought, someone is going to discocer the real thing: Terra Nova, a virtual twin of the Earth, with more-or-less identical environmetal conditions, and located at a relatively small distance remove from our solar system. At that point, we are likely to see some serious developmental work done on long-range non-relativistic space travel technologies. The lure of a new Earth is going to be strong.
And it’s not as far-fetched as one might think. The possibility of some form of “fast” interstellar transportation technology has a fairly sound basis in theoretical physics. From the “warp drive” theories of physicist Miguel Alcubierre to the possibility of Thorne-Visser type artificial wormholes, a large and ever-growing amount of physics literature exists to support the idea of manned, physical interstellar travel. Conventional physics offers its own set of “slow” interstellar travel options, from subtle strategies like self-replicating “viral” Von Neumann probes to brute-force approaches like Dr. Charles Pelligrino’s antimatter-powered “Valkyrie” starships. Finding Terra Nova would create a renewed interest in these and other approaches to interstellar travel. In many ways, a new Earth would be a galactic “Field of Dreams”: if we find it, we will come.
Or not. It is also possible that the human race might react to the discovery of a new Earth in the same way most react to current space exploration: with a shrug. If the general public’s reaction to Terra Nova is a disinterested “So what?”, the odds of any interstellar exploration proposal being funded (either publicly or privtely) will be nil. To the average person space is, at best, the place where the TV channels and weather reports come from, and has nothing to do with their daily lives. Any calls for an expedition to the new world will meet with the same public disdain that current Moon and Mars exploration proposals receive. “We should fix the problems on this Earth before we go and ruin the other one” will likely be the average person’s first reaction to the news of the existence of Earth’s twin.
(And of course if the human race ends up destroying itself in a war or groaning beneath the bootheel of global tyranny, the existence of a second Earth will be meaningless.)
With that in mind, it becomes obvious that the eventual discovery of a new Earth must be accompanied by the establishment of a vigorous and substantial expansion of the private business sphere into space. Government is primarily concerned with fighting wars, collecting taxes, and handing out checks for votes; to expect them to carry out the colonization of space is absurd. It is only by the will of private adventurers that our own solar system will become a habitation of man. As the number of human beings working (and, in time, living) in space and on various planets, moons, and space stations increases, space will cease being the real of sci-fi and satellite porn in the minds of the average person and will become a “place” — a part of the real world of everyday life. And once that happens, the universe outside of our own home planet will truly become a New Frontier.
And a New Frontier is precisely what space must become if humans are to inhabit it. The expansion of private industry into space will not be enough to drive man across the limitless gulf to another star; there will be no money to be made on Terra Nova that could not be easier made here in our own solar system. The quest for profit will drive the settlement of local space, but it will take something more to push man across the sea of stars.
That something will be the desire for fresh fields. In every society, there are some few who have within them the desire to see what lies over the next ridgeline, to go “where no man has gone before” just for the hell of it. The society of our Colonial forebears was no exception. When the pioneers of early North America set off from the comfort and relative security of the Colonies and began the settlement of the West, they were motivated not by greed or politics, but by the desire to start over — to begin life in a new world of endless horizons and unlimited opportunity.
And should a new Earth be found, thse in our society who share with them the pioneer spirit will arise once more. Should Terra Nova be found by a society that has perfected cheap, reliable space travel, a society which still honors the individual and celebrates the explorer, these pioneers will rise up and set out for the new world. Their urge to explore will create a market for technologies that will allow them to do so within the lifetime of a man, and private enterprise will organize itself to supplying this demand. And soon after that, the first starships will set sail.
So what can we do to make sure our society is ready for the discovery of Terra Nova? We can support the efforts of those who are seeking to expand private industry into space. From the planned suborbital tourism of Burt Rutan and Richard Branson to the current orbital (and later lunar) habitat programs of hotel magnate Robert Bigelow, the opportunities to support private space travel with words and dollars are growing every day. For now, we should offer these pioneers our encouragement and public support; in the near future, we will have the opportunity to support them as investors and paying customers. We must also work to keep space exploration on a “going concern” basis in the public eye, by vocally supporting the idea of human beings working and living in space. By promoting the idea that space is just another place, we will reduce the giggle factor that accompanies any serious discussion of space colonization and in so doing hasten the day when the average person considers the sky to be a place where real people can work and live.
Somewhere out there is a world like our own, with blue skies, fields of grain, vast forests, lofty trees, and soaring peaks. Someday, we will find our long dreamt-of Terra Nova. Our job is to keep the dream alive until then.
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Also, what's the formula for a mass' (such as a planet's) gravitation? This is a question for freeperdom in general.
i.e. How'd you find out how much you'd weigh on the planet? And would you actually be that heavy?
Theoretically, an Orion Project-type ship could get there in about 25-40 years. More research should be made into the feasible of FTL travel, though.
What’s the formula (see some of the previous questions)?
What’s the formula for mass/radius to gravitation?
The author could have been getting at: it could be similar to Earth, or it could be completely covered in water.
What’s the formula from mass to Gs?
What’s the formula for gravitation from mass?
Appreciated (for the formulas/formulae).
According to other freepers’ calculations, RB would be around 140 lbs. here on Earth.
So, what’s the formula for gravitational force?
Oh, yeah, an Orion-drive ship would make it there. Relativistic effects would be a b***h and it would be woefully inefficient.
Maybe the Heim drive will pan out.
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