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
We can send the libs there to start fresh!
Good luck to them.
Just think how much Rosie would weigh?
Especially at the relativistic speeds necessary to get there!
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WoW! I like your idea and I like your 'ride.'.........
I'll volunteer to be the camp cook/Sheriff.......
If it moves, I can shoot it. If I shoot it, I can cook it. LOL!
ping
Actually, spunkets' formula is completely correct. It doesn't matter whether the planet has a 10 mile radius or a radius of 1.5 Earths (roughly 6,000 miles), if you are at a distance of 1.5 Earths from the center of mass, the gravitational pull is the same. As spunkets pointed out, the inverse square law applies.
It also doesn't matter that all planets are denser toward the center, than near the surface. Gravitational anomalies (masses at the same depth with different densities) have a slight effect, but they would not be noticable to you.
Rotation would also be insignificant, unless the planet has a very fast rotational velocity. On the Earth's Equator, you are travelling around the Earth at about 1,000 miles per hour, but you can stand at the Equator, or at one of the Poles, and not notice the difference in weight (you are slightly heavier at the Poles).
This is simple Newtonian Statics and Dynamics, which is normally covered in the first quarter of college physics. Those who take physics in high school are likely to learn this before they get to college.
You only weigh 60 pounds?
That’s okay, the colony ship will have a eugenics program to select for skeletal and muscle strength, and will gradually increase its axial rotation to raise the simulated gravity during the trip, which should take about 6400 years travelling 600 mi/sec (approx. escape velocity for the solar system).
(Kind of shows how irrelevant this ‘news’ is when you think about it.)
Because the planet is bigger than Earth you are farther away than the center then on earth. So, someone who weighs 60 pounds on earth would actually weigh around 108 pounds on the other planet.
I know that earth's effect is pretty small. As I recall though, there's a tendency for large-mass solid objects (especially close in ones) to spin like the Dickens at some stage in their development until they transfer their momentum and become tidally locked, which is part of what has happened to the earth because of the moon. I only mentioned it because in certain conditions it might be sufficient to nudge the figures a bit. OTOH, if this thing is close enough in to have a 13 day "year", on an object as long-lived as a red dwarf, it's probably tidal-locked or nearly so.
No, I weigh 190 approx. But since that planet is 1.5 times as big as earth, I’d weigh 1.5 times as much.......
Cool!
Thanks for the ping!
Hey if these scientists can engage in wild speculation ... why not me?
You're correct though. Of course we haven't checked Europa or any of the ice moons with probable liquid oceans.
for the fy 09 budget Bush oughta offer free rides for liberals to this new planet. it would be worth the cost.
FWIW, Shostack is supposed to be on Coast during the first hour, talking about the new discovery.
Also see http://www.space.com/scienceastronomy/070424_hab_exoplanet.html
Quadruple NASA’S budget and direct it to develop propulsive technology...with the side effect that the money can’t go to national healthcare. That would make the Dems go absolutely ape.
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