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Habitable planet found.
NOSLEEP
Member Posts: 4,526
Well... lets get ready to make a move. Dano you can pull the pin any time... [:D]
http://www.cbc.ca/technology/story/2010/09/29/science-habitable-exoplanet-gliese.html
Astronomers believe they have found the first Earth-sized planet outside our solar system that is likely to support liquid water and therefore life.
Planet "g," which orbits a red dwarf star called Gliese 581, is right in the middle of the star's "habitable zone," reported a team led by Steve Vogt of the University of California Santa Cruz and Paul Butler of the Carnegie Institution for Science in Washington, D.C.
Two of the planets previously discovered around that star were right on the edge of the zone around the star that has the possibility of supporting life, giving them only a small chance of being habitable.
The evidence suggests that Planet "g" is a rocky planet with a diameter about 1.2 to 1.4 times larger than Earth's, they said in a paper posted online at arXiv.org, a pre-print archiving service. It will be published in the Astrophysical Journal.
The planet's mass means its gravity would be the same as, or slightly higher than, Earth's, and a person could easily walk upright, Vogt said in a release. That is also enough gravity to hold onto an atmosphere.
The planet is "tidally locked" to the star that it orbits every 37 days, which means one side is always facing the star and one side faces away in perpetual darkness (similar to the way the Earth always faces the same side of the moon). That means that even though the average surface temperature is likely between -31 C and -12 C, one side is extremely hot, and the other side is always freezing cold.
The "most habitable" zone would be right between the light and dark sides.
The characteristics provide a "very compelling case for a potentially habitable planet."
Habitable planets likely common
Given that very few stars have been monitored so far by planet hunters, the researchers believe the discovery of such a planet so soon has wider implications.
"If these are rare, we shouldn't have found one so quickly and so nearby," Vogt said in a statement.
"The number of systems with potentially habitable planets is probably on the order of 10 or 20 per cent, and when you multiply that by the hundreds of billions of stars in the Milky Way, that's a large number. There could be tens of billions of these systems in our galaxy."
Gliese 581 about 20 light years away from Earth in the constellation Libra.
Researchers found the planet by analyzing 11 years of observations with the high resolution eschelle spectrometer on the Keck Telescope at the W.M. Keck Observatory in Hawaii. The spectrometer, which was designed by Vogt, measures the star's radial velocity - that is, its movement toward or away from the Earth. The gravitational pull of orbiting planets can cause a star to wobble.
Because that force depends on the planets' orbits and masses, those characteristics can be teased out from the radial velocity measurements.
http://www.cbc.ca/technology/story/2010/09/29/science-habitable-exoplanet-gliese.html
Astronomers believe they have found the first Earth-sized planet outside our solar system that is likely to support liquid water and therefore life.
Planet "g," which orbits a red dwarf star called Gliese 581, is right in the middle of the star's "habitable zone," reported a team led by Steve Vogt of the University of California Santa Cruz and Paul Butler of the Carnegie Institution for Science in Washington, D.C.
Two of the planets previously discovered around that star were right on the edge of the zone around the star that has the possibility of supporting life, giving them only a small chance of being habitable.
The evidence suggests that Planet "g" is a rocky planet with a diameter about 1.2 to 1.4 times larger than Earth's, they said in a paper posted online at arXiv.org, a pre-print archiving service. It will be published in the Astrophysical Journal.
The planet's mass means its gravity would be the same as, or slightly higher than, Earth's, and a person could easily walk upright, Vogt said in a release. That is also enough gravity to hold onto an atmosphere.
The planet is "tidally locked" to the star that it orbits every 37 days, which means one side is always facing the star and one side faces away in perpetual darkness (similar to the way the Earth always faces the same side of the moon). That means that even though the average surface temperature is likely between -31 C and -12 C, one side is extremely hot, and the other side is always freezing cold.
The "most habitable" zone would be right between the light and dark sides.
The characteristics provide a "very compelling case for a potentially habitable planet."
Habitable planets likely common
Given that very few stars have been monitored so far by planet hunters, the researchers believe the discovery of such a planet so soon has wider implications.
"If these are rare, we shouldn't have found one so quickly and so nearby," Vogt said in a statement.
"The number of systems with potentially habitable planets is probably on the order of 10 or 20 per cent, and when you multiply that by the hundreds of billions of stars in the Milky Way, that's a large number. There could be tens of billions of these systems in our galaxy."
Gliese 581 about 20 light years away from Earth in the constellation Libra.
Researchers found the planet by analyzing 11 years of observations with the high resolution eschelle spectrometer on the Keck Telescope at the W.M. Keck Observatory in Hawaii. The spectrometer, which was designed by Vogt, measures the star's radial velocity - that is, its movement toward or away from the Earth. The gravitational pull of orbiting planets can cause a star to wobble.
Because that force depends on the planets' orbits and masses, those characteristics can be teased out from the radial velocity measurements.
Comments
They called it a "goldilocks" planet. Loved the term!
Where water isn't "too cold" or "too hot" its "just right".[:)]
Could be meat, could be cake. Might be meatcake...
We have both bad news ,and good news.
The bad news is Martians have landed in Chicago.
The good news is they eat Democrats/Liberals,and pee gasoline.
Now back to your regular scheduled program.
Its 3x the size of earth, thus it could have one really dense atmosphere, and be like a super venus.
Its also really really close to its star, for all we know, earlier solar flares have blasted away its atmosphere.
Its star is really really small (0.2% the mass of our sun) - which is how the planet can be so close and not be too close for water to exist. Stars of that size radiate primarily in the infra red, which due to physics and atmospheric properties/absorption spectrum of gasses, mean that photosynthesis is unlikely.
Because it is so close, it is certainly tidally locked to the sun, like the same side of the moon always faces the earth.
So, one side of the planet bakes, the other side freezes.
Where it would be the right temperature, would have the most atmospheric filtering of the sun- again, this doesn't bode well for photosynthesis.
So that leaves only geothermal energy for any potential life.
Suddenly, it looks less about as hospitable to life as Europa- except this planet has a surface that might be habitable, whereas Europa might have an ocean that is habitable for life.
Of course, extreme conditions where only highly specialized life can exist (at least on earth) may not necessarily have life.
Where things can evolve to life, and where abiogenesis can happen, are not the same thing.
If you don't believe in the above, then you can doubt "god created" life on those planets.
So when the astronomer said the probability of life there was 100% (though qualifying that he was an astronomer, not a biologist), he was talking out his * to get more press coverage.
Its also worth noting they've discovered two other planets in the same system, and previously told the press that those planets would be habitable too, only to retract it later.
Are we to believe this third claim, when the 2 before it were premature?
Sensationalist BS by someone looking for more funding.
Reality TV often has "celebrity" series/episodes, I propose a "politicians" survivor series.
Sure, the rocket to get there will cost hundreds of billions to trillions, and take practically forever (if we got fusion working, we could get to a speed of about 0.2c, and its 20 light years away, which gives a minimum time of 100 years, but you'd have to decelerate too, so you'd realistically get to 0.1c tops, so that makes it 200 years, and given how slow the acceleration is, lets say a millennium to get there)
Sure, we'd need to get cryogenics working, and I'm not a fan of technology that keeps politicians around longer, but if they are still around, 20 light years away, I can deal with that.
If we got cryogenics, but not fusion, a fission/nuclear powered craft with a VASMIR engine could probably get there in 5 millenium.
Definitely would be the most awesome survivor series ever, so would the 1-5 millennium before it airs, where we are free of our politicians.
Would be great for them to get there, and find the atmosphere about as hospitable as that of Venus, or Europa's (as in almost non existent).
Drop them off at the "terminator" (the line of perpetual twilight/perpetual sunrise/set in between the hemispheres of perpetual day and perpetual night)
By SETH BORENSTEIN, AP Science Writer Seth Borenstein, Ap Science Writer - Wed Sep 29, 7:19 pm ET
WASHINGTON - Astronomers say they have for the first time spotted a planet beyond our own in what is sometimes called the Goldilocks zone for life: Not too hot, not too cold. Juuuust right.
Not too far from its star, not too close. So it could contain liquid water. The planet itself is neither too big nor too small for the proper surface, gravity and atmosphere.
It's just right. Just like Earth.
I not gonna go and pack my bags just yet.
Margaret Thatcher
"There are three kinds of lies: lies, damned lies and statistics."
Mark Twain
It's still a stretch to say that a planet would be habitable just because it's in the "habitable zone". There is quite a difference between "lighting", and "lighting bug".
I not gonna go and pack my bags just yet.
Its a bit of a stretch to confirm all of what has been said of this new discovery thats for sure. But it does give hope to the theory we are not alone and in the universe and life may be right next door in the grand scale of things.
Red Dwarf Stars like this make up 90% of all the stars in the galaxy.
To be close enough to the star to be warm enough to have liquid water, means you must be so close the planet becomes tidally locked, like the moon is to the earth, on side always facing the sun, one side always facing away.
On side freezes, the other bakes.
Its even worse when you consider that it could get so cold on the freezing side, that even nitrogen, carbon dioxide, oxygen, etc, freeze, just like the ice caps locked up water in the ice age, and lowered seal levels, the ice on the dark side (that is *always* dark, will lock away more and more atmosphere, convective heating is less, and it accelerates....
You end up with an atmosphere-less inhospitable ball.
Any Red Dwarf is a bad place to look for life.
There is a remote possiblity that the planet could have a thick enough atmosphere to keep the dark side from freezing (due to convection), but theres a fine line between that and Venus.
The absence of a thermal day/night cycle makes it much less likely life could spontaneously arise there, as thermal cycling is one way to replicate molecules outside of a living cell (we do it in the lab all the time with nucleic acids - its known as PCR).
I expect that this planet is quite barren (even the best foreseeable technology- Proton-Helium fusion rockets, would take at least a hundred years to get there), but we will never know (unless we meet aliens who have already been there).
A high resolution eschelle spectrometer on the Keck Telescope is chump compared to my spotting scope.
My property taxes helped pay for that Eschelle spectrometer that I don't have access to![:D]
Just as there is a "goldilocks zone" around a star, the Milkyway has a "goldilocks zone" too.
Too close to the center, and there is too much X rays, to many stars passing close enough to other planetary systems to fling planets out of their orbits (careening off into empty space), too far from the galactic center, and you dont find anything but helium and hydrogen, not nearly enough of the elements like needs (at a minimum, Carbon, Nitrogen, Oxygen, Phosphorous)
Then there are the stars that are bigger than the sun, size inversely correlates with lifespan of stars, red dwarfs are so dim because they are barely massive enough to trigger fusion, really massive stars burn really bright, and fast (relatively speaking), they also don't have as constant of an output (output increasingly much faster) A planet on the coldest limit of the habitable zone, may find itself at the hottest limit, in less than a billion years (earth 4 billion years, still pretty much right in the middle of it).
Other star types are prone to "coronal mass ejections" (giant solar flares), which would blast away the atmosphere of planets in the habitable zone.
And that also doesn't take into account the peak output shifting towards the UV - you'd need one heck of an ozone layer to protect you on land or within a few feet of the waters surface, and ozone layers cant form without photosynthetic life already being present.
Then there are variable stars, whos habitable zone moves outward and inward, a planet may find itself frozen, or baked, when it was previously just right, in only a few thousand years.
Red giants would have swallowed up any previously habitable planet candidate, and anything in the zone of the short(relatively) lived red giant won't have much time for life to advance in complexity (using the rate earth's life has as a gauge).
Most stars aren't even the right type.
Of those that are the right type, most are not in the right place in the galaxy (note, we are in the right place, so our neighbors are a good place to look, but don't assume because you find one with life close, that the distribution is similar throughout the galaxy)
Then keep in mind, during planet formation, a planet won't get much of an atmosphere, as it will be too darn hot, and it won't yet have a magnetic field to protect from the solar wind.
Any planet in the "goldilocks zone" will likely require extensive bombardment by commets and such to deliver the liquids and gasses needed for life.
That may require an appropriately positioned gas giant (or giants, ie Jupiter, or Jupiter, Saturn, and the others) to displace objects from the Oort clouds.
And then there is precession about the planets axis - you know how earths axis is tilted? well that tilt doesn't vary much (it does more on the other smaller planets and moons)
Well thats because we have a moon, it stabilizes the axial tilt.
We have the biggest moon relative to planet size known, and that was a product of a planatoid forming at one of Earths la grange points.
We also can speculate that perhaps tidal mixing (provided by the moon), was a requirement for life to start.
Further it may not be enough just to have phosphorous and nitrogen:
Without a radioactive core, even though we are bigger than mars, it would have cooled down by now, we'd have a much weaker magnetic field, and our atmosphere would be blown away and be nearly as thin as that of mars- vapor pressure drops, good by water (water cannot exist as a liquid in a vacuum, no matter the temperature).
We may need to be in a part of the galaxy that has really heavy elements, like Uranium (indeed at one point in earths history, Uranium concentration was so high, that natural fission reactors were operating - which would have produced some interesting chemical reactions, and one can also wonder if this was a condition that allowed life on earth to happen, and without it, earth would be lifeless - see also "radioactive beach hypothesis")
So the galactic habitable zone may be even slimmer than we think.
Without plate tectonics, nutrient cycling wouldn't work, and earth would start to grow barren really fast (relatively speaking) - its hypothesized the collision that resulted in the moon, may have caused the plate subduction and convection system to start.
There are sooooo many oddities of Earth, that may or may not have been what pushed conditions over the threshold, or laid the groundwork, for life to arise on this planet.
We cannot know what exactly was needed....
And then there is more needed to spawn multicellular life, if life has been here for 4 billion years, 3.5 of that had no multicullular life - what caused the change?
When one asks if we are alone, I must say, I don't consider pond scum much of a companion to cure loneliness.
The "Rare Earth Hypothesis" dictates that places habitable to life are somewhat common (though not nearly as much as the early renditions of the drake equation lead us to believe), but life itself is much less common, and complex multicellular life, very uncommon, intelligent life... perhaps we are unique *within our galaxy*
But if we don't accept life as being really rare in the galaxy, it leads to the Fermi Paradox.
In short.... where are they...
Once a species can master fusion, they should be able to spread throughout the galaxy in less than 2 million years.... we've had life on earth for 4,000 million years.
Where are they? unless there isa *huge* co-incidence in when they got started, and when we did, they should have been here by now, for eons, they should be everywhere you look in the galaxy.... unless their civ didn't last that long, which doesn't bode well for earth.
There are three solutions for the Fermi Paradox:
1) They are everywhere, we just don't know what to look for (I don't find this convincing - especially since any object above zero kelvin will radiate in the infrared, any alien ship will stand out like a torch against the backdrop of space http://weirdsciences.net/2010/01/18/there-aint-no-stealth-in-space/)
2) Civilizations always collapse before becoming space faring (I find this pessimistic)
3) Intelligent life is really rare, and we may be the first in the Galaxy (I find this the most desirable outcome)