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Extrasolar Planet Could Harbor Life
Posted by
Zonk
on Fri May 18, 2007 01:22 PM
from the hello-up-there dept.
from the hello-up-there dept.
BlueMorpho writes with a link to a Space.com article about a recently discovered extrasolar planet that may be able to harbor 'life as we know it.' Orbiting around the star Gliese 581 is a small rocky ball that might have the same liquid ocean and drifting continent configuration we're familiar with. The find may be unique in all of space exploration as this planet appears to be within a habitable band of temperatures for life, and is categorically not a gas giant. "The bottom line is exciting ...The conditions for life could be there, but is life itself? As yet, there's no way to know unless the planet has spawned beings that are at least as clever as we are. As part of the SETI Institute's Project Phoenix, we twice aimed large antennas in the direction of Gliese 581, hoping to pick up a signal that would bespeak technology ... Neither search turned up a signal."
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Transit Method Reveals Many Extrasolar Planets 174 comments
eldavojohn writes "You might recall not too long ago the first photo of an extra solar planet or, more recently, the mapping & speculation on these planets that lie outside our own solar system. Long since those first few spotted in the 90s, we're now starting to find them in droves due to the popularity of a method that relies on the planet passing directly between the viewer on earth and the star that it orbits. Be sure to check out Space.com's list of the most interesting extra-solar planets. Will we ever find Earth 2.0 candidates?"
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Oh my god, it's full of dupes. (Score:5, Funny)
Re: (Score:3, Funny)
The best neighbors... (Score:5, Funny)
Re:The best neighbors... (Score:4, Funny)
Parent
The trouble is (Score:5, Funny)
The trouble is that despite the planet's title sounding like a science fiction title, the former residents of Gliese 581 were at least as clever as we are, and the planet is currently recovering from a complete nuclear winter...
Re: (Score:3, Interesting)
Doesn't SETI focus on a specific band of the EM spectrum that is not polluted by solar radiation and thus an obvious place for any sentient beings on another world to broadcast a signal that would allow themselves to be found?
The follow up question being: Are we broadcasting such a signal at that frequency?
Seems like if we're assuming whatever sentient beings out there think like us and thus we can deduce what they would do to be found, t
Re:The trouble is (Score:5, Interesting)
The answers are, respectively, yes, and no. Though we have made a heck of a lot of noise at other frequencies, and the earliest of those signals are very roughly about 100 light-years out by now. They would be extremely weak and difficult to detect, though with a large enough space-based antenna system, it is certainly doable if they listen in the right direction. Signals that have gotten about 50 light years out are much more powerful; they've reached fewer stars, of course.
I suspect that our "window" of using RF transmissions through the air will close within another century or so. There are better, more reliable things available to us such as fiber; almost incomprehensibly higher bandwidth by virtue of one fiber being able to lie next to another, not so easy when using RF, better availability, much more difficult to interfere with, more efficient in terms of energy required in use... RF just doesn't make a huge amount of sense for broadcast, and this is becoming more so every day. And I say that with a certain degree of regret, being an extra-class ham radio operator who grew up with the romance - no, really, I'm serious, romance! - of radio signals fading in and out from all over the world.
It is what we'd do - we're not doing it for political reasons, not scientific or technical reasons. It has been proposed over and over that we broadcast; and has been turned down every time. The question is, do we want to invite visitors? It is one thing to be curious to see if you have neighbors, and to learn the answer without disturbing them or letting them know we're here; it is entirely something else to let them know we're here, or to invite them over - as unlikely as that seems given what we know of physics today. Considering that it is unlikely, it would be all the more intimidating if someone from the Sirius system, just to pluck one out of a hat, heard our signal and a day after they heard it there, they showed up here. The question is, what would they show up with if their physics are that good? All they really need is the ability to shove a few large rocks in our direction and they could go home snickering about those silly primates that used to live on Sol 3... that concerns a lot of people. Some earth species are quite aggressive and territorial, and man is one of them. Looking at our own behavior, it doesn't seem too conservative to think that the same might apply to someone else. So the politics are knotty.
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My argument against this reasoning (Score:3, Interesting)
Sure, space aliens from planet X that came to visit us would have to be be way more advanced than us. Sure they could wipe us out in a heartbeat.
But, why would they bother?
Why would a race so far advanced, bother to travel so far just to wipe ot some inconsequential race? There is nothing we would have that they would want. Any resources available on Earth they would be able to harvest from any number of other places closer and more convenient gi
Re: (Score:3, Interesting)
While the number of planets in our galaxy is huge, the probability of a planet having a composition and climate similar to that of Earth's is extremely remote.
Can you elaborate on that? Why would it be remote? Do you have any way to estimate the probability?
On top of that, the probability of life forming on that planet is also very remote
Again, can you justify this claim? I am not disputing your claim, I just have no idea how can the probability of this be calculated. I have seen people making this claim several times already, however, none of them ever seemed to care to support the claim with at least some estimate.
and on top of that, the probability that life would have evolved along a similar timeline is also very remote.
That I can agree with.
Re:The trouble is (Score:4, Interesting)
1. Our sun's positioning in this galaxy is basically perfect. We're between two of the 'arms' of the milky way. Meaning we're nestled safely away from the gravitational chaos of other stars that may want to rip us out of our orbit around the center of our galaxy. So that rules out many places in our galaxy. Not saying there isn't a chance. I'm just saying that theoretically, the planets in there may be screwed some time in the future. Most other galaxy styles don't have a 'safe harbor' like this.
2.Earth itself has so many favorable factors for it that it is astounding. The tilt of our axis makes for an optimal environment for life across our whole planet. I remember reading that many astrologers estimate that just a half a degree either way and we'd have much larger ice caps or a band of uninhabitable desert. Our elliptical, almost circular, orbit keeps us in the most comfortable spot. A million miles either way and we'd be toastier or colder. Life could still exist, but it would be less than 'ideal'.
As I understand it, our ferrous core spinning at slightly different speed creates our Van Alen Belts to protect from solar wind.
We have an asteroid belt that has protected us from undoubtedly billions of asteroids over the millennial of Earths existence.
Our tidal locked moon pulls on the oceans causing the Earth to continue spinning at a proper speed to maintain life.
How' that? When you consider all this, and the probabilities being of this happening elsewhere (or just 'enough')... you can pretty well give up hope. But there isn't any fun in that! I'm all for looking for hospitable planets. This universe is fascinating. What a waste to not explore?!
Parent
Re:The trouble is (Score:4, Insightful)
Look out, your anthropomorphism is showing. True, it is unlikely that humans would have resulted from adaptation to an environment different than our own. But that's how adaptation works.
We may very well find "life" on planets that fall far outside your narrow definition of it -- but, as Dr. McCoy said, "not as we know it".
Parent
Anthropomorphize much? (Score:5, Insightful)
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Re: (Score:3)
Re: (Score:3, Interesting)
Actually, a recent study suggests that we are passing sideways through this galaxy.
I'm not sure how relevant this is anyway, but let's move on.
Irrelevant: we don
Re:The trouble is (Score:5, Interesting)
I think you need to recheck some of your facts.
Our solar system moves in and out of the spiral arms as well as up and down through the galactic plane [cornell.edu]. We go through the galactic plane about every 35 million years, and through the spiral arms about every 100 million years. Some postulate that these timescales coincide with various mass extinctions that occurred.
The axial tilt of the Earth changes all the time. The tilt angle varies between 22 and 25 degrees over a period of about 41000 years. There is also precession of the orbit that happens on a 22000 year timescale. The changing tilt angle changes the severity of the seasons (length of seasons, ice ages, etc.), but it doesn't have anything to say about whether the planet could harbor life.
There isn't anything magical about our molten core and magnetosphere. We usually expect large rocky planets to have them, so we find it unusual if a planet doesn't have a magnetosphere.
I wouldn't say that the asteroid belt has protected us. The asteroid belt is basically a planet that either didn't form, or didn't survive. Its existence is probably one of the biggest threats to our survival on this planet. It is a race to see whether a large asteroid or comet hits our planet and wipes us out. Nobody doubts that it will happen again in the future; we just don't know when it will.
The Moon actually causes a drag on the planet that is slowing down the Earth rotation. I don't recall hearing what an ideal rotation rate for the Earth is to sustain life.
Once one gets their head around how many stars there are in just our own galaxy, many people consider it a given that there is life all around in the galaxy. Even if you take the most pessimistic odds for life to develop, once you multiply that by the number of stars out there it would seem to be very likely. The most famous statement of this is the Drake Equation [activemind.com]. Of course, once you consider the extremely large distances between any two stars it is easy to come to the conclusion that all this life will not come in contact with each other (the intelligent life, that is).
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Re: (Score:3, Insightful)
- Arthur C. Clarke
Re: (Score:3, Insightful)
We also know that life exists presently in ecological niches that are far from "human ideal"; right here, there are life-forms in volcanic vents, in the depths of tar pits, at the tops of mountains and at both poles.
The entire "life as we know it" argument needs to actually pay attention to life as we know it, because that includes residence in a considerable range of environments, and with some wildly varying nutritional and/or respiratory requirements.
The good news is, no person's opinion on this m
Re:The trouble is (Score:4, Insightful)
Parent
Re: (Score:3, Funny)
Seriously, if I were of a peaceful, technologically advanced society, I wouldn't want to communicate with Earth, either. Worst case scenario, the less friendly humans get ahold of alien technology and we start mucking up OTHER species' homes.
Re: (Score:3, Funny)
Not to the Corporations rushing to patent alien genes and technology... no matter how loud the aliens call 'prior art' or obvious.
I just hope the only time we hear from an alien race is when the earth is about to be destroyed to make way for an intergalactic high
Re:The trouble is (Score:5, Funny)
Parent
Re: (Score:3, Insightful)
Oh, please, have you never chirped at a bird?
Re:The trouble is (Score:4, Funny)
Or maybe they don't want to communicate with us because they read slashdot.
Parent
Space/Genetic Exploration (Score:5, Funny)
Re:Space/Genetic Exploration (Score:5, Interesting)
The medical science and technology might the easy part compared to interstellar travel though.
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In all seriousness, getting the flu isn't nearly as likely as simple anaphylactic shock.
Re:Space/Genetic Exploration (Score:5, Informative)
Try and imagine dutch elm disease making the transition from trees to humans. Then remember that both host organisms are terrestrial - we're more closely related to trees than we would be to any alien. It's not totally impossible that some alien bacteria could, by some chance, find the human body hospitable (or vice versa), but it isn't very probable.
Plus, the human immune system has a habit of attacking anything remotely foreign. That's why you get problems like allergies and organ rejection. If an alien organism is enough like us to pose an infection risk, then it's also most likely similar enough to trigger an immune response. And the diseases that we face today have had millions of years of evolution to prepare them for our immune system, whereas anything alien has not. So even if life elsewhere is very much like life here, it'll have the same catching up to do that we will. Admittedly pathogens evolve faster than their hosts, but then again these hosts have medical technology to make up the difference.
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Re:Space/Genetic Exploration (Score:4, Funny)
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Re:Space/Genetic Exploration (Score:4, Informative)
1. Highly infectious diseases behave that way because they jump from a species in which it has coevolved (HCV in humans, Influenza in birds, various other diseases in pigs, rats, insects, etc), and so become not-terribly-pathogenic and suddenly entered a situation where it can jump species to another host. The extreme death rate of these diseases is a direct consequence of the fact that they DIDN'T evolve in the presence of humans, and that the new host behaves in an entirely unfamiliar manner to the foreign viral strain. Killing every organism it comes across is a horrible way for a virus to survive - the ideal is to achieve a minimal killing rate such that it becomes endemic to the population, with only a small proportion falling ill and dying. As such, our hypothetical alien virus has the potential to behave in this manner, provided the alien host is biochemically similar to us in one or more of the modes of entry for the viral strain. Admittedly, this only gives the potential for a mutant strain that could mess you up, but it's the same idea as Influenza - most truly common strains can't hurt you, but repeated contact with it in close quarters can give rise to an infectious system. Now, the true argument here is that it's unlikely that these hypothetical alien species we run into will have similar cell-surface proteins or modes of entry into the body - but simply arguing that a virus cannot infect a species it's never seen is a naive and deceptive idea. The far greater danger is...
2. Infectious microbes. The alien equivalent of bacteria, fungus, protozoa, worms, etc. It is quite likely that we will encounter a species which benefits from growing in a human-like environment, most likely some kind of warm, damp tissue bed. Find a rapidly growing strain of alien microbe which digests its food externally, mix well with a human mucus lining, and you very rapidly have the potential for a flesh eating species. Equally likely is that one of the common hormones fed out into the air by alien critters (think of the compounds produced by plants et al for communication) behaves as a carcinogen to the naive human metabolism, or acts as some kind of hormone mimic. Industry produces such compounds all the time, not to mention legitimate toxins on Earth - there's no way of saying that the air on a warm spring's day on an alien world wouldn't be lethal to us due to immediate and violent immune responses to the foreign contaminants. There are many possibilities about what alien organisms might do to us, and it's silly to think that just because we've never seen it, it won't cause some kind of mass physiological response.
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Re: (Score:3, Interesting)
Bacteria, in contrast, do 80-100% of the work themselves. They can actively invade -- move in a directed manner -- and can physically attach themselves to cells and start doing damage. Helicobacter pylori, for instance (the bacterium that causes many ulcers) is shaped like a screw and physic
Needless hype: good publicity or bad conditioning? (Score:5, Interesting)
When the media flogs "science" stories like this, full of marginal ideas that probably aren't true are we just conditioning the public to ignore actual science as pie in the sky crap? Or does the break from Paris Hilton news stories have some tangible benefit to educating society at large?
Re:Needless hype: good publicity or bad conditioni (Score:5, Interesting)
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Re: (Score:3, Informative)
Re:Needless hype: good publicity or bad conditioni (Score:3, Insightful)
No, we're also inspiring another generation of kids to enter scientific fields. Seriously, how much does stuff like this pique the interest of the next Goddard, or even the next rank-and-file NASA employee? Or maybe the next Branson, who is willing to spend a fortune of private funds on space-related activities (even if he do
No Signals != No Life (Score:4, Insightful)
Because tiny microbes living in the soil always emit "signals". Technologically advanced life vs. life are two very different things. Jetson's like colonies would be nice to find, but honestly, we are more likely to find single cell organisms who haven't quite figured out how to build a radio tower.
Re:No Signals != No Life (Score:4, Insightful)
Parent
Might be hell to live on... (Score:5, Interesting)
A "year" where the planet rotates around the star is only 13 days. If tidally locked, a "day" is the same amount of time.
The same tidal forces would also make any large oceans on the surface prone to immense tides. The strong tides may also result in more tectonic activity than on Earth.
Re:Might be hell to live on... (Score:4, Informative)
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Complete and Utter Failure (Score:5, Funny)
The first interspace wardriving attempt thus ended in failure. The Gliesians must be hardwired.
Re: (Score:3, Funny)
The first interspace wardriving attempt thus ended in failure. The Gliesians must be hardwired.
Nah, they're just using appletalk just like Jeff Goldblume said. (hachoo)
exciting time for astronomy (Score:3)
uh-oh (Score:5, Funny)
They had their firewall on. (Score:3, Funny)
Let's be real... (Score:5, Funny)
The actual exchange...
EARTH: How are you?
GLIESE 581: Sorry, we don't need Viagra. You can try the next planet over.
SETI is a joke (Score:4, Insightful)
Basically, if the Aracaibo telescope were on Gliese and were pointed at Earth, it wouldn't detect us. Until the SETI project gets a better telescope, the fact that we didn't detect anything coming from Gliese when we pointed one of our ground-based radio telescopes at it only means they aren't stupid enough to spend a billion dollars to build a 20MW directional transmitter, point it right at the earth, and leave it blasting for thousands of years hoping we'd give a listen.
Re:Quick... (Score:5, Funny)
"I can picture in my mind a world without war, a world without hate. And I can picture us attacking that world, because they'd never expect it."
Parent
Re:kill the aliens (Score:5, Funny)
Well, I'm pretty sure the little green men will do one of the following:
a) Disable our colony ships main computer with a computer virus written quickly by one of their hacker geniuses and then hit it with a nuclear warhead while our colonists are waiting for Windows to boot up again.
b) Find out that a very common, harmless (to them) substance on their planet is highly toxic to us humans and douse any unwelcome visitor with it.
c) Realize that their equivalent of the common cold is a deadly plague for humans.
d) Send in the little green men in black to take care of the human invasion, then mind-wipe any innocent bystanders.
e) Travel back in time and keep Earth from forming.
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Re:Afraid (Score:4, Funny)
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Re: (Score:3, Funny)