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
And all news stories that have to do with anything else, for that matter.
I don't think that's quite right. Your equation supposes that the mass is all at a singular point and that you are suspended/supported on a massless sphere 1.5 earth radii away. To figure it out precisely, you may need to include rotation speed as well (depending upon whether it is fast enough to be significant).
"Two great ladies will catch your fall, they are the ones who catch us all. Their children kept them far apart; the Lady Light, the Lady Dark. Dark broken, light storm, dead spoken, dreams torn... and we will bring you home."
How fast does it rotate on its axis?
What is the angle of its axis?
I bet they're really strong there.
Does the mass of the planet directly corelate to the atmosheric pressure?
atmospheric......
“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.
AWESOME .... probably about 2 - 2.5G on the surface but if it's got liquid water it's got life.
What's ironic as hell is that red dwarfs are the most common star out there. We could be the exception (having a main sequence star primary) rather than the rule.
Of course it's probably tidally locked which will limit the habitable portions of the planet as well.
Weather patterns should be interesting as well.
“orbits a red dwarf”
I can see how that’d make it easier to find, but wow, how unlikely is it that something the right size and composition would also be in the star’s itsy bitsy habitable zone.
Just wow.
A red dwarf's solar wind is pretty pathetic compared to the sun's
Tides are something with which I have a fair familiarity. I seem to remember that there is a way that moons can be detected on faraway planets like this one, though it’s not mentioned in the article.
You’re right about the angular momentum. THe planet’s round though. So I’d expect the order of magnitude for that kind of a correction to be smaller by less than 2. Earth’s is ~0.3% at the equator.
There could be a good basis for these things. We roughly know what mass the star is since we know it’s luminosity and its distance. In turn, we can tell what the planet’s mass is by the motion of Gleise around their mutual centers of gravity. The orbital period is simply the time it takes for the star to make a single complete “wobble.”
This takes a bit of computation since the wobble we want to measure has to be sifted out from the larger effects of the larger Neptune class planet, but it can be done without too much hassle. Since we know the distance from the star, the star’s energy output, and the planet’s mass, we can say whether or not the world lies in the “habitable zone” wherein liquid water can exist in an equilibrium environment.
The presence of water is suspected on account of current models of the growth and evolution of planetary systems. We won’t know for sure until one of the proposed next-generation spectrometers is launched, but that seems more likely now that we have a definite target, and one that’s pretty close by to boot!
That is, of course, providing there aren't any illegals there. LOL!
A space shuttle would leave too big of a carbon footprint. Better if we send him in a one man Mercury capsule.
Note to everyone. Gravitational force scales with radius as well as mass.
F = G(m1)(m2)/R^2
The force experience there by someone on the new world with mass M is
F1 = G(M)(5m(Earth))/(1.5R(earth))^2
The force experience here on earth is
F2 = G(M)(m(Earth))/(R(earth))^2
The ratio of these two forces is:
F1/F2 = 5/(1.5)^2 = 2.22..
So a 150 lb man here would weigh about 333 lb there. It’s a big difference, it would certainly be inconvenient for us, but it wouldn’t be lethal for a wide variety of earthborn species.
LOL, typos
Also, a planet so close to it’s sun would be tidally locked, i.e. the same part of the planet would always face it, much like the same side of the moon always faces Earth (this is true for most moons of every planet in the solar system) therefore making one side of the planet super-hot and the other ice cold.
Space ping!
So we have to round up potential (almost prenatal) NFL offensive lineman to send there?
Maybe, maybe not. Mercury isn’t tidally locked, and it’s a lot closer to the Sun than this planet is claimed to be. The planet isn’t likely to be a pleasant place though. With liquid water on the surface and such close proximity to the host star, there’s a strong chance that the planet will have tidal action in the oceans driven by the star itself. The Earth does experience tidal effects in the seas due to our own Sun, but they are largely invisible due to the much stronger tidal pull of our moon. Since the tidal pull of our own sun is 46% the strength of the tidal pull of our moon, one can only imagine the tidal pull a star would exert on the liquid surface of a planetary body 14 times closer.
It’s true that X-rays and tidal locking would be a huge problem for life on a rocky planet but aquatic life might survive with water to provide some protection from the radiation and also to serve to spread the heat around.
I will take your word for it LOL!
For what it’s worth, 120 miles is 20.4 light years.
Assuming current technolgy, a massive effort to build a nuclear-pulse engine and space craft(probably could be done in 10-15 years time, if we REALLY got after it) -— say by a benevolent dictator of USA that was really into space.
I bet a voyage would take 30 years one-way, our relativistic time, (5 years to accellerate, 5 to decellerate, 20 years or so at 3/4 speed of light).
Let’s go visit and find out.
I’m thinking women would really need bed rest during the last trimester.
A newborn baby! A mere 32lbs!
Red Sun? Greater gravity? Might have to be kinda strong huh to get around?
hmmmmm
.....models predict that the planet should be either rocky – like our Earth – or covered with oceans,”...
Fifty fifty chance . The man could recall that earth has both
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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