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Exoplanet Count Tops 700
astroengine writes "On Friday, the Extrasolar Planets Encyclopedia registered more than 700 confirmed exoplanets. Although this is an amazing milestone, it won't be long until the 'first thousand' are confirmed. Only two months ago, the encyclopedia — administered by astrobiologist Jean Schneider of the Paris-Meudon Observatory — registered 600 confirmed alien worlds. Since then, there has been a slew of announcements including the addition of a batch of 50 exoplanets by the European Southern Observatory's High Accuracy Radial velocity Planet Searcher (or HARPS) in September."
And 1024, and 1337
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
could've sworn it was there a few months ago... anyone know what happened to it?
I just spend the weekend at a family gathering. Many of my relatives are doctors, scientists, and professors. The topic of alien life came up, and almost all of them laughed it off! Now I'm merely a computer programmer so I didn't say much, but when I hear about there being hundreds of exoplants out there in space I can't help but think that there may be life on at least some of them. After all, these are only the planets that we know about so far! There are probably millions upon millions of other similar planets out there that we just haven't discovered yet.
Why do well-educated scientists consider alien life, even if it's very simple or nothing like life here on earth, to be such an absurd idea? Why do they have so much trouble considering it with any seriousness?
Because if what we've found so far is at least a somewhat representative sample, the overwhelming majority of planets tend to be either gas giants, frozen balls of rock and ice, or roasted balls of rock and lava. You have to be terribly imaginative to see life coming up on worlds like that.
Of course, even if we go by 1 in 700, or 1 in a million for that matter, the Milky way ought to be positively teeming with life. We simply don't have enough data to make a meaningful conclusion either way yet.
Why do well-educated scientists consider alien life, even if it's very simple or nothing like life here on earth, to be such an absurd idea? Why do they have so much trouble considering it with any seriousness?
The scientists in your family may not be representative of scientists in general.
I've always assumed that most people who know the numbers involved think that alien life must exist (with a hundred billion stars per galaxy and hundred billion galaxies, it seem like there are pretty good odds).
Whether we'll communicate with, travel to, or be visited by aliens is an entirely different question with a lot more scope for doubt.
The English word fart is one of the oldest words in the English vocabulary.
I've always assumed that most people who know the numbers involved think that alien life must exist (with a hundred billion stars per galaxy and hundred billion galaxies, it seem like there are pretty good odds).
Part of the problem is that some people use 'alien life' to mean anything from microbe-sized upwards while others use it to mean 'little grey men in flying saucers'. The former is almost certain to exist, but there's no evidence for the latter and good reason to believe that they don't exist; technology merely a few thousand years ahead of ours should be visible across much of the galaxy.
If you consider how many times the scientists have been wrong in history, you'll have a pretty good guess.
Now non-scientists have been wrong too, so it's closer to say "humans have been wrong".
Bottom line: we actually don't know. There may, or may not be alien life. Heck, we don't understand the universe either.
We often pretend to be the best specie there is, because we kill all the other ones we've found so far (which makes it fun as we are afraid another specie from space would do that to us lol). And that therefore, we'd know a lot already. The thing is, we don't have really a scale of things, or if any, we're meaningless compared to the universe.
But we know that what we've found so far is NOT a representative sample, because the methods are biasied towards finding jupiter-sized planets?
There are scientists and there are scientists. If the scientists in your family scoff at the idea of alien life then their opinions may not have been well considered. There are plenty of very credible thinkers who feel quite certain that we will one day find life off the earth - Stephen Hawking among them. People who scoff at ideas which seem far fetched just because they seem far fetched have a history of looking quite red faced when later they turn out to be wrong. The earth is flat and the centre of the universe, and the Newtonian world being just two famous examples. It goes all the way back to the earliest discussions on the nature of matter. Greek philospher Democritus was criticised for his ridiculous idea that matter consisted of 'atoms'. We may or may not find other life in the universe, but to dismiss it as impossible is just silly.
That's not really good reason to believe they don't exist. A galactic spanning civilization, for one, would only be visible, as you say, across the galaxy. Not across the entire universe. And secondly, as of right now it is only a pipe dream that a couple thousand more years of history will spread us across the stars. We might just as easily blow ourselves up, retreat into a cyber-singularity, or just run out of gas, so to speak.
But anyway, I agree that it's likely that microbial life of various sorts is abundant. And on the other end, I've always felt that it is only a kind of cellular chauvinism that prevents us from thinking of stellar objects as life forms. They grow, they mantain homeostasis, they sometimes reproduce in a fashion, they consume, they die.
There are two kinds of people: 1) those who start arrays with one and 1) those who start them with zero.
"Because if what we've found so far is at least a somewhat representative sample, the overwhelming majority of planets tend to be either gas giants, frozen balls of rock and ice, or roasted balls of rock and lava. You have to be terribly imaginative to see life coming up on worlds like that."
There are plenty of life forms that live in unusual environments right here on this planet. Geothermal vent ecosystems for example:
Deep-sea bacteria form the base of a varied food chain that includes shrimp, tubeworms, clams, fish, crabs, and octopi. All of these animals must be adapted to endure the extreme environment of the vents -- complete darkness; water temperatures ranging from 2C (in ambient seawater) to about 400C (at the vent openings); pressures hundreds of times that at sea level; and high concentrations of sulfides and other noxious chemicals.
http://science.nasa.gov/science-news/science-at-nasa/2001/ast13apr_1/
There are also bacteria that live in sulphuric acid in caves.
http://dsc.discovery.com/convergence/planet-earth/guide/caves.html
It isn't unreasonable to think that life may have evolved in unusual environments elsewhere.
Not really. Basically, as soon as our methods allow to detect lower-mass planets we immediately detect them.
It's just that now our tools are not yet good enough to detect Earth-sized planets in habitable zone.
Where do you get the idea that scientists don't believe in extraterrestrial life?
The more planets and potentially earth-like planets we discover, the more paradoxical the Fermi paradox becomes: "where are they?"
How would we see a Dyson Sphere if it's capturing all the output from their star? It would be just another patch of blackness against the inky black of space. Our small slice of space we can view at any given time is very tiny, frequently changing, and we can't actually see most of these exoplanets, just their effect causing their stars to wobble. We'd have no hope of seeing satellites around a planet, or space shuttles, or even a space ship the size of one of the Alliance citadel style things in Firefly, with current technology, unless they were within the inner solar system, or buzzed a probe in the outer system. We might see something very large if it deliberately silhouetted itself against Jupiter, for us.
Admit it. You post strawman arguments as AC so you get modded Insightful for refuting them, rather than Troll
Were they laughing off the idea of extraterrestrial life itself, or the stuff you commonly see in popular culture...you know, the people who treat Roswell like a Mecca, go on about grays and abductions and crop circles, anyone who agrees with Ancient Aliens Guy, ect.? It is one thing to speculate that, out of countless stars, it is possible that there exists more than one planet with some sort of life (while admitting that there is no evidence whatsoever to indicate that that is the case and acknowledging our general lack data), and it is hard to say that such an idea deserves to be dismissed outright, however the idea has certainty attracted more than its fair share of things to be rightly laughed off. I never really noticed that scientists completely dismiss the notion of non-terrestrial life, if anything, I'd have assumed just the opposite is true. I'd guess that either your relatives are not representative of scientists as a whole for one reason or another, just chose to go with what evidence is actually verifiable rather than get into the whole 'billions of stars times non-zero possibility of life equals...' thing, were thinking not of the concept itself but of of the nonsense various spacey nutters go on about, or just didn't want to look like said nutters in front of everyone else by acknowledging the possibility.
"You have to be terribly imaginative to see life coming up on worlds like that."
Um... no you don't. There are even theories out there for life that could exist inside a stars corona.
Just speculating that the context of the discussion matters a lot. Maybe they felt a lot of peer pressure to discredit the idea, since they were all together. Or it could be that they are sick of real kooks talking about aliens. "Aliens" is different than "life". Aliens is Sigourney Weaver.
A relative of mine worked at an public observatory/science center for many years in a big city. He had to deal with a lot of loonies who know what flavor of ice cream the aliens like. Many feel a very religious connection with "aliens". Perhaps they pick this up from movies. From a scientific POV this has more to do with human psychology than exobiology. It's a part of our culture, and it's a difficult place to start from if you want to get at the truth.
Earth biology is a science we know comparatively little about. Exobiology is so speculative, you could run a lot of very expensive experiments, come up empty, and not have scratched the surface or have proved anything either way. Experiments that don't prove anything unless you hit a very unlikely home run are easy to laugh off. There could be a billion planets out there, full of life, or we could be alone. It doesn't change the odds when we don't even know what we are talking about.
It kind of makes SETI look like a waste of time. I guess it's worth doing, but it's like pissing in the ocean.
We can restate the original premise. Our methods are biased towards finding large planets close to stars.
Given the limits of our current techniques, it should be possible to quantify the limits of their resolution. Put this together with some models of solar system formation and we can extrapolate our observations using a model that says X% of all planetary discs tend to evolve into systems with large planets that migrate in toward their sun. So 1-X remain in some other state. perhaps one we can't detect (yet).
Have gnu, will travel.
Look, my friends said it is very very likely not that it was 100% sure (they are scientists after all!). I mean that's a very reasonable stance to take considering that there are about a 100 billion stars in our galaxy, and about a trillion stars in the OBSERVABLE universe (the actual universe is likely to be MUCH larger, maybe infinite). Considering the large proportion of stars that seem to have planets and the billions of years they've been around it, doesn't it seem very VERY likely that life would have started more than once?
Flip a coin several trillion times. What's the chance that it won't come up heads more than once?
Of course I've read "Rare Earth" AND his other book "Life, But not as we know it" in which he says life could've arisen not just on earth but on Mars, Europa, Enceladus and maybe THREE TIMES on Titan! So while he is (rightfully) concerned that COMPLEX life is "rare" (but not impossible) he also seems to think that (simple) alien life is present almost everywhere!
Also, my chemist friend is in the geological sciences dept. of his university and works with experts in the fields of extremeophiles. As for the others, please realize that science is not a vacuum, at least not at the level that they practice it and they follow major developments in other fields both directly and indirectly; they, to varying degrees, have an excellent idea as to what's going on. (My computational linguist friend probably knows the details of the transit studies, he's the kind of guy who learned a difficult Asian language on his spare time while raising a couple kids while developing algorithms so sophisticated he has to give the state dept. one month advance notice before leaving the country).
Actually I'm beginning to think that the people who claim that their educated brethren say that we are unique have their own, belief based, agenda to push. Whatever.
It's also possible that numerous civilisations with a similar level of technology to ours exist, but it's simply impossible in practice to "colonise the galazy". Inter-stellar travel may simply require too much energy/resources, or it may turn out to be infeasible to survive in space for long enough for anybody to reach another star.
The existence of extraterrestrial life is completely philosophical and hypothetical. Saying that such-a-such scientist does or does not think there is otherworldly life is not proof one way or another, even if that scientist is decorated or the great Hawking, whom I admire. We can discuss the size of the universe, the number of stars and discuss it from a statistical point of view. The math involved does lead to the probable conclusion that extraterrestrial life must exist, but this is again not proof. As for the idea that "galactic spanning civilizations" must be seen from our small rock is human arrogance. There is a strong possibility that such a civilization exists and our current technology simply cannot detect it. As for question of celestial bodies and stellar objects being life forms, we don't know that they are non-sentient. that is a philosophical question of another kind. What definition of life do we use?
Not to mention objects with really short orbits, which means much more rapid observations. Any planet will only pass between the star and us once per cycle (assuming it's in the plane) which makes it much easier to find orbits measures in weeks or months instead of years and decades. Like for example our Jupiter has an orbit of almost 12 years. They need two measurements to get a period and want three for confirmation, that's 36 years. How long have we been searching for exoplanets again? Oh right, we wouldn't have found our own solar system yet.
Live today, because you never know what tomorrow brings
Gas giants can't form close to stars, they have to migrate towards them.
That too is in question. To understand why we see so many Jupiter-sized planets you really need to understand the techniques we use to detect them.
http://en.wikipedia.org/wiki/Methods_of_detecting_extrasolar_planets#Established_detection_methods
For some methods fully confirming a planet requires more than one orbit. Their orbit may be measured in years, decades or centuries. For other methods it's a one off event and we can't confirm the existence of the planet. The first confirmed planets were detected around a pulsar (a kind of dead star) only in 1992. And the method used only worked for pulsars. It took until 1995 to detect a planet around a main sequence star.
http://en.wikipedia.org/wiki/Extrasolar_planet
Then it took years to get dedicated space instruments up. Effectively we've been at this only for 17 years. Given the difficulty that's nothing. Give it time! Perhaps your grandkids will grow up with earth sized planets confirmed.
These posts express my own personal views, not those of my employer
Yes. Niven addressed this in the sequel by adding massive engines to the ring that stabilizes it.
If you believe the geological models of the rise of life on Earth, I find it very telling that life came about so rapidly.
3.8 billion years ago, the earth was probably still molten rock.
Sometime after that, water started to condense on the surface.
3.5 billion years ago, we find fossils for single cellular life. The surface temperature was still high, there was still much exposed molten lava, the day was only 15 hours, radiation blasted the surface incessantly... but life existed in only the first 0.5% of the wet Earth's lifespan.
The odds of life being extraordinarily unique on Earth, yet popping up within the first 0.5% of the time that there was water on the surface leads me to believe that life is almost inevitable when given the right circumstances.
That really lends more credence to the idea that it might eventually happen elsewhere.
Now, complex life... no idea. There's no way to know how rare that actually is.
I will announce it when it reaches 81680085
hilarious
there's simply no (rational) reason not to abandon your meatbag and migrate to a more robust and easily maintained container.
Boobies.
-- Counting backwards since 1984!
Or was the discussion about UFO's and aliens landing and probing peoples' rectums? That would pretty much deserve derisive laughter.
They certainly won't show up with anal probes.
I wouldn't be so sure. If aliens did have the technology to visit our planet, why wouldn't they want to grab a few specimens, take us apart and see how we worked? After all, we do the exact same thing to every new organism we come across. Sure, some of them may have tech so advanced they can just point a scanner at us without us even knowing, and find everything they want to know. Others may not be quite as advanced; they may have the spaceflight bit down, but not the medical tech part. I think some sci-fi author once wrote a book about some unfriendly aliens that visit the earth with advanced spacecraft and then attack using basically 1500s-era cannons, because they never developed very advanced weaponry. While that's probably a bit absurd (I think it's safe to assume that hostile species (like us) would spend more resources developing weaponry than other technologies, so their weaponry would be just as advanced as their spaceflight ability), the idea is sound: different civilizations aren't going to develop technologies at the same rates. It'll be dependent on their cultural values, and also their availability of resources. Some aliens may push much harder on spaceflight technologies and not very much on biological/medical technologies. Just look at us: we could be decades more advanced in spaceflight tech than we are now, but as a species we just don't think it's very important so we stopped bothering so much with it about 40 years ago, and instead we've been concentrating on computer tech and finance, and some medical tech. Perhaps some aliens have visited us that happened to stumble upon some bit of physics that we totally missed (like wormholes, interdimensional travel, etc.), and used this to establish a spaceflight program that allows them to visit other planets at FTL speeds, but their other tech isn't much more advanced than our own. They might come here and think our spaceflight tech is crap and laughable, but be amazed by our 3D games and simulators and very interested in our upcoming graphene semiconductors. (Who knows, maybe we've already discovered the bit of physics necessary, but the guy who discovered it wasn't able to get peer-reviewed and his dissertation ended up on a library shelf somewhere, never to be read...)
Of course, given the timescales involved, it's probably more likely that anyone we meet will be far beyond our own tech, but there's no way to know. Since we haven't met any other cultures yet (that we know of), it's really premature to make any assumptions at all as we have zero basis for comparison.