Slashdot Mirror
Billions of Planets In Milky Way?
jeffsenter writes, "The Washington Post has the story: 'NASA scientists using the Hubble Space Telescope have discovered what they believe are 16 new planets deep in the Milky Way, leading them to conclude there are probably billions of planets spread throughout the galaxy.' What sets these potential planets apart is they are in the central bulge of the Milky Way where most stars are located. More planets in the galaxy means more chances for life." The 16 are planet candidates at this point, until verified by spectroscopic measurement of their parent stars' wobbles, which probably can't be done until the James Webb Space Telescope files in 2013.
Harbouring what form of life exactly.
Common sense suggests that there are billions of planets in the galaxy, and that millions of them could harbour life, and that thousands of them have significant evolved life and a few have intelligent (tool using or above) life. That's just playing with numbers and likelihoods and the belief that we're not a one off.
But this just shows that there are lots of large gas giants. Maybe there's life on their moons...
In Soviet Russia, space telescope looks at YOU!
I don't reply to Anonymous posts; if you have something to say to me, identify yourself or I won't reply.
I think the best way to contact aliens and let them know we are here is to build a giant billboard about 10x bigger than the sun that says "Hey aliens, people live here" and park it right outside out solar system. That way when they're looking at us with their giant telescopes, they'd see it and know. I'm sure we could get pepsi to sponsor that billboard, they sponsor anything. As for us seeing other intelligent life, just watch for planets to spontaniously blow themselves up. I'm sure we'll almost do that a few times in the future looking at the past so logically some aliens have to do it.
Is it just me or is it not going to upgrade to Vista in here?
I work for the Shuttle program. The current plan is to send up a Hubble repair mission. Can't say when, but it's definitely planned.
Fuck my accountant. I'm getting an astronomer.
Eloi are stupid, throw morlocks at them!
Oh wait, that's the 1-AU-wide super-sized Snickers bar.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
This is a great example of a ground-based telescope that could easily rival any space telescope:
OWL Telescope
Even lower -- 1 in 200 if every star has only one planet. If we go with an average of 5, then it's just 1 in 1000.
William of Ockham had no beard. The most likely explanation is that it was chewed off by squirrels every morning.
I think that's because space manufacturing hasn't been made a reality yet. I think once mirrors or even optical lenses are made in zero-gravity in a place where size isn't nearly so important, space-borne telescopes could well out-perform the earth-based.
The slant on the slashdot summary is kind of goofy. Actually, the central bulge of the galaxy is a lousy place to look for life. There's a good book about this: Rare Earth: Why Complex Life Is Uncommon in the Universe, by Ward and Brownlee. It looks to me like the author of TFA went out of his way to highlight the life angle, which wasn't that significant, and then the slashdot submitter highlighted it even more, as if it was the main point.
Find free books.
It's because you can't draw conclusions from a sample size of 1. Suppose that you've spent your whole life in a blue room. You know there are other rooms out there- but can you assume that they are all blue? Can you assume that most of them are blue? Even if there are other blue rooms, would they be the same shade (Cerulean, let's say) as yours?
Even assuming that we are not unique, there is a big difference between thousands of stars with planets and billions of stars with planets.
You are reading a copy of my copyrighted post.
SETI's odds are very poor on this score.
Ah, but the most kick ass telescope would be one located on the far side of the moon. No earth light to interefere and, to quote a book "This place has no atmosphere". With the 1/6th gravity, the mirrors could be much larger as well.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
how meny of them have stargates on them?
How come we'll believe someone when they say that there are billions of planets in the galaxy, but when we're told that paint is wet we have to touch it - just to make sure
*''I can't believe it's not a hyperlink.''
I'm curious how this will help nail down some of the parameters for the famous Drake Equation N = R* * Fp * Ne * Fl * Fi * Fc * L.This new guestimate will help narrow down f sub p, the fraction of stars that have planets, and go some distance to narrowing down n sub e, the number of planets that can support life per star. As our resolution power increases the better able we will be able to come up with better guestimates.
The answer might be zero anyway. After proposing the equation Fermi pointed out if intelligent life is so common, where are they? A space faring civilization travelling at 1% the speed of light would cross the galaxy in ten million years. Relative to the age of the Milky Way Galaxy, ten million years is a very short period of time. This is called the Fermi Paradox. Where are they?
I think we just don't know enough yet and we haven't been looking for very long. I think our technology will help us give a more accurate answer to the Drake equation within the next 100 years. We may even find evidence of life on other worlds when we can detect free oxygen on worlds in habitable zones light years away. And that could happen within the next decade or two.
For those people who say the aliens are already here, I would ask would an intelligent space faring civilization travel hundreds of light years just to kidnap some redneck farmer and give him an anal probe and then make crop circles in his fields? I suppose if it was some alien fratboy hazing ritual they would.
"You'll get nothing, and you'll like it!"
The 16 are planet candidates at this point, until verified by spectroscopic measurement of their parent stars' wobbles, which probably can't be done until the James Webb Space Telescope files in 2013.
A detection of Doppler motion due to planetary perturbation is miniscule. It could take an accuracy of less than one km/s, or more likely a few dozen meter per second. It is extremely hard to make a high resolution spectroscopic instrument for a space satellite to meet that criterion. Calibrating out all the uncertainties in the motion of the satellite would become an issue as well. That said, I don't think the James Webb ST would do much in this topic.
Besides, the designers for JWST don't strongly desire to have a spectrographic instrument on board the JWST. It may end up as a purely imaging mission, which is extremely boring for physicists.
The verification is better done with adaptive optics + Echelle grating at V, R or IR band from ground.
The article said these findings were based on 7 days of observations, using the transit method. In this method, the planet passes in front of the star, causing a very small, but sudden and periodic drop in the brightness of the star. Presumably, they don't claim to have a candidate unless they see multiple dimming events. If so, the longest possible orbit they could have observed is 7 days, meaning the planets are extremely close to their stars. Even their moons would be inhospitable.
However, as another poster pointed out, these systems may also harbor smaller planets in more favorable orbits. In fact, some researchers believe that smaller rocky worlds can only form with the assistance of disturbances created by the gas giants.
In contrast, other researchers are skeptical that planets can form at all in the inner regions of the galaxy because of the high star density. Even if they did, they might not be able to harbor life because of all the radiation from said stars.
As another poster pointed out, however, we don't necessarily know the limits of conditions that life may form. This is getting a rather fanciful, but perhaps high-temperature silicon-based rock monsters are real, like Season 4, episode 7 where Kirk fought the lava man with the Abe Lincoln avatar (just kidding, I made that up...or did I?).
Spinning liquids to form mirrors works on Earth because Earth's gravity acts perpendicular to the plane of spin. We would need some way of replicating those two forces in space. All the methods I know about would cost more than simply launching a solid mirror.
A method of putting cheap mirrors into space that I proposed to my physics mentor a few decades ago is to use inflatable mirrors. He brushed off the idea at the time. Now, though, NASA has research on the general concept:
NASA Tech: Parabolic Membrane-Thickness Variation for Inflatable Mirror
A Google search for inflatable mirrors turns up many more results.
Taking stuff apart since 1969 (TM)
Who was burned at the stake for saying precisely this by the creationists of his days. That was persecution, not the phantom "book banning" that today's creationists crybabies complain about. Nowadays, hopefully they have lost their power; do not let them conquer it again...