Earthlike Planet Orbiting Nearby Star 617
The Bad Astronomer writes "Astronomers in Europe have announced the discovery of a planet with only 5 times the Earth's mass, orbiting a red dwarf star 20 light years away. It orbits the star so closely that it only takes 13 days to go around... but the star is so cool that the temperature of the planet is between 0 and 40 Celsius. At this temperature there could be liquid water. Models indicate the planet is either rocky like the Earth or covered in an ocean. While it's not known if there actually is liquid water on the planet, this is a really big discovery, and indicates that we are getting ever closer to finding another Earth orbiting an alien star."
When do tickets go on sale? (Score:5, Interesting)
What I think is the coolest thing is that this is the smallest extrasolar planet found so far. We are getting close to being able to detect earth-sized planets. Once we do, I think the number of potentially colonizable planets will go up quite a bit.
This is worth sending a probe. (Score:5, Interesting)
if you create a probe with an ion drive and send it off in the next 10 years we could be looking at surveys of the planet in question by 2070.
My Hope (Score:2, Interesting)
Re:How long to get there? (Score:3, Interesting)
Re:Uninhabital new worlds (Score:5, Interesting)
Also remember that were you got the information on gravitational pull and the atmosphere for this planet is speculative at best.
1) 2.25 times that of our own gravitational pull would not be ideal for us to live but, it doesn't mean nothing could live there. I pull 2.25g's with my car on a dry skid pad, I have not died yet.
2) Really?
3) Yes the planet is closer to its sun that ours, but if this planet is like ours, the atmosphere filters out most of the radiation. The star closest to them does not spit out the magnitude of radiation that ours does due to its size.
4) If there is atmosphere like ours with water in it, it will hold some of the heat as it passes out of its suns rays and therefore should be just as turbulent.
Also some things to think about:
Even if the planet is 2 times as big as our planet, it could be spinning faster than ours. This would help off set the gravitational pull on our bodies at the surface.
No one is saying this is a planet to colonize, but with some of our technology and determination, it could be a waypoint in the stars for us to refuel and grab water before we continue our adventures further into space.
Just my two cents,
-X
Re:This is worth sending a probe. (Score:3, Interesting)
as opposed to all of the other bloated governments out there?
then it communicates back data by laser
Please sit down and do the math. Do you realize the pointing requirements for what you suggest. With the best tech we have the laser would be swinging between Pluto and the Sun thinking it was right on target.
still, this is within the realm of practicality, and if it returns promising results it could usher in a new era of colonization.
right... and I might bang three supermodels this weekend (number selected only based on a low prime number).
Science fiction is a wonderful thing to contemplate but keep your pants on. No such mission is feasible within the lifetime of anyone on this planet.
I wonder how the sun would look... (Score:2, Interesting)
Probably not tidally locked. (Score:4, Interesting)
2.25 gees is uncomfortable but tolerable (carry someone your own weight piggyback and you're almost there), and largely irrelevant to any water-dwelling critters.
However, the larger problem -- that I didn't see any of the articles explicitly raise -- it that there's likely a Venus-like greenhouse with the temperature much hotter than the 0-40C based on the equilibrium temperature of a rocky body at that distance from the primary. We can hope not, but we'd need a reason why not.
Based on our system, anything Venus-size or larger has a thick atmosphere, except Earth, and Earth is an anomaly because it got whacked by something massive (Mars mass) late in its formation, blowing most of the volatiles -- and the material that makes up the Moon -- off the planet altogether. (However, such late-stage super-impacts may be not all that unusual; it could explain some other oddities of our system, such as Uranus's tilt.)
Re:Uninhabital new worlds (Score:2, Interesting)
Re:How long to get there? (Score:5, Interesting)
Two other words: Relativity, and Acceleration.
I've read[1] that if we accelerate consistently at 1G we'll reach 0.77 C in 1 year. However, as we continue to accelerate closer to C, we get more and more relativistic and things get screwy... screwy to the point that I'll estimate it would take about 6 years (that's 6 rocket years, not earth observer years) to get there, with 1G accel and 1G deccel. So, human travel would be extremely feasible.
While a probe could accelerate much harder, I figure it would still take 50 years or so to get results from a probe to confirm it's worth sending people.
1. http://www2.corepower.com:8080/~relfaq/rocket.htm
Re:Probably not tidally locked. (Score:2, Interesting)
ion drives and the speed of light (Score:3, Interesting)
if you create a probe with an ion drive and send it off in the next 10 years we could be looking at surveys of the planet in question by 2070.
Again, correct me if I'm wrong but according to http://nmp.nasa.gov/ds1/tech/ionpropfaq.html [nasa.gov], ion drives only deliver 10x the efficiency of chemical rockets. So to reach 0.6c, wouldn't an ion drive require more propellant than exists in the universe?
Re:How long to get there? (Score:5, Interesting)
Re:When do tickets go on sale? (Score:2, Interesting)
Re:Probably not tidally locked. (Score:4, Interesting)
I'm a sucker for this kind of news, so I'll be waiting until somebody can measure and report results with a major presence of either CO2, nitrogen, methane, whatever's there. But then again, Gliese 581 is a red dwarf, has it gone through a red giant stage? If so, any atmosphere may have been blasted into deep space.
Then again, maybe atmospheres can regenerate through the leaking of gases from beneath the planetary crust, volcanic-style, and with 2.5 G's, I would imagine it wouldn't drift into space on its' own very easily. If so, a red dwarf may be extremely stable, creating an exponentially longer window for life on systems like these than with a main-sequence system like our own. But obviously, this is completely speculative territory.
Re:How long to get there? (Score:3, Interesting)
The Calculus result after you take the limit is physically meaningless, in my opinion. It only tells you what's happening as you get close to the speed of light, not when you hit the speed of light.
If you didn't understand what I just said, pick up a decent Modern Physics textbook and study the relations. Then argue away.
Re:quick maths on gravity (Score:3, Interesting)
The star is only about 47%-56% enriched as our Sun in elements heavier than hydrogen, so it stands to reason that any planets that formed around the star are similarly deficient in heavy elements/metals. See the following web page about the star, but keep in mind it has not been updated with this latest planetary information:
http://www.solstation.com/stars/gl581.htm [solstation.com]Tidal Lock (Score:1, Interesting)
A planet orbiting this close will likely be in tidal lock with one side always facing the star. This would have unplesant effects on any atmosphere.
Semi-inhabital new worlds (Score:4, Interesting)
I am aware of one experiment of putting someone in a high-G centerfuge and subjecting him to 1.5G's. The experiment was terminated early, due to the participant having a mild heart attack. Keep in mind, the participant wasn't given time to acclimate to the new environment gradually, and the experiment was short in duration, lasting only about a week, as it was designed more towards seeing if a high-G environment could help astronauts overcome loss of muscle mass and bone decalcification faster than normal after returning to earth, rather than colonization of a high-G environment.
Re:Probably not tidally locked. (Score:5, Interesting)
2) Yes, most planets do leak gasses, although the rates and gasses vary greatly, as does what is retained.
3) Red dwarfs are extremely stable. They burn their fuel extremely slowly. Gliese 581 will be burning long after the sun given up.
Re:How long to get there? (Score:5, Interesting)
What about space dust? INAA (I'm not an astro-physicist)but I don't think that the main problem is a lack of speed. Eventually we will work out how to go faster and faster. For me the problem is those little bits of rock and grit in the way. Even at 0.75C travelling in the not-quite empty vastness of space would be like standing in front of a machine gun going full-on.
Re:Um, yeah, *liquid* (Score:3, Interesting)
Unless this planet also had a collision with a similarly sized planetoid (such as is speculated with the Earth and the current favored theory of the creation of the Moon) that would have stripped much of the original atmosphere away, I don't see how this planet could have a lower pressure atmosphere than found on the Earth and likely would be much higher.
What would be interesting would be to find out what the density of this planet could be. A highly dense object (aka this huge mass and nearly the same size of the Earth) would have a huge surface gravity, but if this planet were mainly made up of water or other lighter compounds, it would be a "waterworld" that would be several times the size of the earth in terms of area and may even have Earth-like gravity on the surface.
Regardless, nearly any possible model you could come up with here would have sufficient atmosphere to allow water in a liquid state at these temperatures. The only exception would be if the atmosphere was so dense like Venus that run-away greenhouse gasses would make the surface temperatures far too hot. Venus doesn't get that much more additional sunlight (measured in watts/cm^3) than the Earth, but it is much hotter than even the surface of Mercury.
Re:Semi-inhabital new worlds (Score:2, Interesting)
Re:My Hope (Score:1, Interesting)
If one ran across a non-stamp-collector who spent as much effort inveighing against philately as some atheists spend ranting against religion, one might reasonably conclude that, for that non-stamp-collector, non-stamp-collecting was indeed a hobby, or the functional equivalent of a hobby.
Re:Only one thing to do! (Score:2, Interesting)
Re:Uninhabital new worlds (Score:3, Interesting)