Earth-Like Planet That Could Sustain Life Found 575
astroengine writes "An exoplanet, 20 to 50 percent the mass of Earth, has been discovered 20 light-years away and it appears to have all the ingredients conducive to sustaining life. It has enough gravitational clout to hold onto an atmosphere and it orbits well within the 'Goldilocks Zone' of its parent star. However, it would be a very different place to Earth; it is tidally locked to its star, creating one perpetual day on the world. Interestingly, this may also boost the life-giving qualities of the exoplanet, creating stable temperatures in its atmosphere."
Good... (Score:1, Interesting)
Only 20 light years??? (Score:5, Interesting)
20 light years is millimeters of astrophysical distance.
It amazes me we have been observing space so long and yet we only now have detected this planet.
It just goes to show how incredibly likely it is to find planets like Earth everywhere in the galaxy.
Humans are so fragile...if only we were hardier (Score:4, Interesting)
Time dilation woes. (Score:5, Interesting)
My math might be a little off, but if we accelerated at g half-way there and decelerated at g for the rest of the way, it would only take a ship about 6.04 years to get there. But thanks to Einstein ruining all our space travel fun with relativity, we of us left on Earth would think the journey took 21.86 years. So there and back would seem like 43.7 years to us.
And the odds of habitable aren't that great (Score:1, Interesting)
Tidally locked means that even with an atmosphere the dark side will be *very* cold and
most of the water will likely end up frozen on the dark side of the planet.
temperature (Score:3, Interesting)
"Interestingly, this may also boost the life-giving qualities of the exoplanet, creating stable temperatures in its atmosphere."
I don't get why that boosts life-giving qualities.
Having unstable temperatures in our atmosphere doesn't seem to have impeded life.
In fact stable temperatures may be a bad thing.
It takes instability to produce the mixing of organic molecules that result in biomass. Lightning. Tidal flow. Wind.
But there's no indication this new planet lacks those. Except the tidal part. Unless it has a big moon. And water.
I work with 2 of the authors (Score:5, Interesting)
I actually work quite closely with 2 of the authors of the paper that reports these results. Any questions? I'll try to respond to posts between now and 2 October.
Re:And the odds of habitable aren't that great (Score:5, Interesting)
We're here not just because we're in the Goldilocks zone, but also because we're a double-planet (earth and moon). Lots of gravitational stress to help encourage crustal slip along fault lines, and free water to help with the slippage. A runaway greenhouse effect caused by much higher CO2 concentrations converts the water to H2SO4. Once the water is gone (it's still liquid at depth even at 150C because of the pressure), the plates lock up completely, and you get Venus.
The moon may be relevant (Score:3, Interesting)
Right on. I would even add that perhaps the moon is fundamental to the creation of life.
There was a time when the moon was much closer to the earth, when tides were hundreds of meters high.
There are theories that life might have been created first when some clay crystals with the right shape got stuck with some complex organic molecules.
Maybe if there were no moon, then no complex organic molecules would have reached the right clays.
According to the accepted theories, the moon may have been created in a freak accident, when a Mars-sized planet hit the earth in the early solar system. The combination of a moon-forming impact with being right in the liquid water zone could be an improbable event.
bored now, with space exploration (Score:3, Interesting)
I'm much more interested in the possibilities of exploring alternate Earths. Somewhere, I'm just SURE I'll find a world where everyone in the U.S. uses the evolved form of the Amiga, with Dvorak keyboards in Esperanto. And the metric system. I'm dying for a McDonalds Royale (hold the cheese and pickles), with a medium Dr. Pepper with pure cane sugar (no ice).
Maybe the alternate world in Fringe will be a good start, only less fascist. I love the dirigibles and the NYC skyline.
Re:Venus and Mars (Score:3, Interesting)
I could just be talking out of my ass, though.
Stability vs stagnation (Score:2, Interesting)
Re:Stability vs stagnation (Score:3, Interesting)
Re:The chances are pretty much zero (Score:3, Interesting)
We have only ONE place that we know life flourishes.
Also, the star is a red dwarf. Besides being plentiful fodder for jokes involving the word "smeghead" [urbandictionary.com], it also means that the star burns a lot cooler than the one we're currently parked next to. I'm also fairly sure that the folks eyeballing this thing would have taken the whole "it has an atmosphere but doesn't rotate" thing into account as well.
No idea if tidal locking always means no plate tectonics, though. I'd be wondering how life would get along w/o a magnetic field to shield it from UV and hard radiation (though that would depend on the spectrum put out by the star in question...)
Re:why do stable chances increase the likelyhood? (Score:3, Interesting)
I thought life & evolution and development thrived on change..
Evolutionary change seems to be enhanced by environmental change, yes, but life itself is an entirely separate matter. Life doesn't have to be complex or evolve rapidly in order to simply exist. In 3.5 gigayears, life on Earth has gone from matted plankton [wikipedia.org] to, well, people. In the same period of time, life on this planet might have gone from matted plankton to really matted plankton. But it would still be life.
the 'kickstart' of inorganic->organic chemistry, presumably took some random event, a one in five gazzillion possible combination of elements
Actually, that's pretty much the exact opposite of contemporary thinking; due to the amazingly rapid appearance of life here on Earth, it's now considered that the sort of self-sustaining chemical reactions that lead to what we call life are quite probable. Not a "one in five gazzillion" chance, but a near certitude. Which is why we expect to find evidence of life (probably extinct) on Mars, and (maybe-not-extinct) in the subsurface oceans of Europa [wikipedia.org].
Re:I work with 2 of the authors (Score:1, Interesting)
Yea, questions.
According to the several articles I have read, one side always faces the sun, so there is no day/night. How does that affect plant and animal life?
There are only narrow bands of area where certain tropic specific life can exist. Go outside those bands and the temperatures vary tremendously requiring other types of life in each specific band. Is this really that conducive for life to evolve?
The author says that the planet is quite stable. I wander if that is actually true, given what we know about it. Yahoo said that the average surface temp ranges to blazing hot on the side that faces the sun to super freezing on the "always" dark side. Along with one side always facing the sun, that would produce some super bizarre weather patterns... The author has no ability to measure atmosphere, but if it did, given these extreme conditions, how would they affect whatever atmosphere there is? Would it make weather extremely violent and unstable, or stable? From what I understand about weather, currents and etc, this has the markings of a vairly violent weather system, if one would exist. How would that affect the ability for life to evolve?
coincidences... (Score:1, Interesting)
So, first we have reports about UFOs sightings over nuclear silos, then the UN appointing an Alien Ambassador (promptly denied), and then a nearby life-sustaining planet is announced...
Hmmm.... if they start rerunning ALF on prime time, we're in business!
Re:I work with 2 of the authors (Score:3, Interesting)
Can you explain, in layman's terms, how you determined the planet was tidally locked with its sun?
Re:The chances are pretty much zero (Score:3, Interesting)
tidally locked isn't necessarily a bad thing. It guarantees that there's a "habitable ring" around the planet that is between the hot and cold side's temps, and its unchanging. So in some respects, it's better than earth here where we have to get used to day/night shifts. Look at what say, the desert does from noon to midnight, huge temp swings. It also means it doesn't have seasons since it's rotational axis is perpendicular to its orbital path. (consider the vast differences we get on the majority of the earth due to change in season) So not only do you have a wide variety of temperatures, but they're almost absolutely stable.
And really, once life gets going and has time to start evolving and improving its ability to adapt, the limits of temperature in general matter less and less and life just spreads out to colonize before-unclaimed territory.
Re:I work with 2 of the authors (Score:4, Interesting)
Honestly, that conclusion was a bit premature. The other coauthors (including my coworkers) avoided speculating on this point.
His conclusion was based on the idea that where liquid water can be present, so far we have always found life to within out ability to identify it. Thus, since there seems some high probability that liquid water *could* exist on this planet (though no evidence thereof, yet---it just seems likely due to the temperature and because water is such a simple and universally common molecule), and where we've found water we've found life (even in circumstances that would be considered unpleasant), he jumped to saying life was likely.
I personally think that it is premature to speculate on life in this system, since so little evidence is available. If pushed to make a call by Vegas, I'd have to say life was more likely than not on this planet, but my line would not be near 100%. Probably closer to 60/40.
Re:I work with 2 of the authors (Score:4, Interesting)
Is there any meaningful insight into the balance of elements in the stellar system (from looking at the spectra of the star) that would help guess the composition of the rocky planets - would there be plenty of the right stuff for life? I ask because I read Gliese is 7-11 billion years old and older stars have less heavy elements, I'd guess that the system would not have the same abundance of metals and heavier elements.
Does the spectra of a star give any clues to the abundance of water in the star system? At least upper and lower bounds?
Tidal Lock = no Life (Score:2, Interesting)
Look, I performed some of the first in-depth analysis of the Gliese 876 system. The inner two planets there are tidally-locked- there's no independent rotation. One side is searing hot (and thus barren), and the other side is frozen solid. The fact of the matter is that abiogenesis (as we understand it) requires a dynamic, liquid/gas H2O environment. This guy's shenanigans about "stable zones" existing between the hot and the cold is utter bullshit. Even if life could develop and then evolve to exist in the "stable zones", you have to remember that this isn't a single planet solar system. The gravitational influence of the other planets coupled with a fast orbital period could cause our poor 581g to wobble even under tidal lock; this would cause the "stable zones" on 581g to shift. In other words, there would be no stable zones. Self-replicating molecules as we know them would not even have the chance to chemically bootstrap.
Re:Only 20 light years??? (Score:4, Interesting)
The only way for humans to get to another star is to learn how to live in space. It is not so daunting a task as most believe. The most important fact is that space is not empty. There are more resources in the asteroid belt then currently exist on Earth and the vast distances between the stars are filled with resources that dwarf the already immense asteroid belt.
It is all out there waiting for us. With the current rate of innovation, I would expect that we are only a few generations away from taking our first real steps into conquering our solar system. After that, it will be only a few more generations until we start spreading out into the beyond. We are really only missing a few key ingredients to take those first steps, most importantly we lack the political/social will to explore space.
It will not be cheap to move into space, but the upside is supercalifragalistic (seriously, couldn't think of a better word). It will mark the beginning of our post-scarcity existence.
If we don't move into space, we will continue to mark time until the end of our existence.
Re:Annddd.... (Score:5, Interesting)
There is an argument to be made that because of the very physics of the universe that life itself may be not only inevitable but practically guaranteed. This statement is made with consideration of organic chemistry and the pervasiveness with which hydrocarbons not only exist but seem to interact and react to other hydrocarbons. Carl Sagan was the biggest proponent of this hypothesis, that the physical laws of the universe predispose the creation of life. If the hypothesis is correct, that hydrocarbons are so common throughout the universe (which they are) and that their interaction to form amino acids and the basis of life itself is the end result of the laws of the universe (supposition at best) then if a planet is the right temperature, has water and carbon then life should form. (note mars isn't warm enough and has no free water and Venus is way way to warm, but Titan is literally covered in lakes of liquid hydrocarbons)
I agree the guy is a bad scientist for making such a claim, but if you believe this line of reasoning then if you can find a star with planets in the habitable zone, the right size, with water and enough carbon then you will have life "guaranteed". They are just on the cusp of having enough technology to see earth size planets, I think it will be just a mater of time till they can spectrograph the light bouncing off the planet and can find out which ones have oxygen in the atmosphere. Once you find oxygen you know you have life, at least minimal enough life to create free oxygen which can't exist without life because of it's highly reactive nature. I believe Carl was right, that life is an inevitable consequence of the universe, but until we have a better understanding of exosolar planets and that our solar system(and the earth itself with it's super-sized moon and high rotation) isn't unique we don't have the ability to say life is guaranteed anywhere and that's what makes his assertion so silly even if he believes Carl's hypothesis.
It's an interesting area, because you could test the theory. With some massive expenditures of cash it would be possible to stop the run away greenhouse effect on Venus. Once the planet cooled it would rapidly lose much of it's excess atmosphere and attain a condition not that much different than the early earth except for the very slow rotation and lack of a moon. That test would then prove whether the moon (tidal forces) and fast rotation (short nights) were special or essential in the creation of life. If those two variances are important than life could still be quite rare even with the universal predisposition to life from the right physical circumstances. It's been argued that life first started in the tidal pools on earth, without tides you don't get the periodic flooding that life in the current tidal pools needs to survive. Whether life can survive nights that last multiple days or even weeks is another argument that has little to no evidence to support.
Anyway, I don't agree with the scientists affirmation but I do understand why he would believe so strongly that life is guaranteed if the conditions are right.
Re:The moon may be relevant (Score:3, Interesting)