Dusty Disc May Mean Other Earths 289
DoraLives writes "According to the BBC, astronomers say they have evidence for Earth-like planets orbiting a nearby star. The star in question is Vega, which is nice and close (as stars go), quite young (also as stars go), and one of the brightest stars in the sky. Apparently, 'Vega has a disc of dust circling it, and at least one large planet which could sweep debris aside allowing smaller worlds like Earth to exist.' Should be interesting to keep an eye on it as the years roll by as the disk rotates and our optical powers keep growing."
to bad we're looking in the past (Score:1, Interesting)
woah...Carl Sagan was right!!!! (Score:3, Interesting)
Not the first, (Score:3, Interesting)
I'm still all about developing a means of getting us out there to explore these places.
Plus, it would certainly be nice to finally find a backup for our planet. You can't tell me there aren't at least a few people out there who have been rather alarmed at all of our recent unexpected solar activity.
Damon,
Probably not "finished" terrestrial planets yet... (Score:4, Interesting)
If you send a probe there, it will not be able to find a cool surface on any of the larger planetesimals (growing proto-planets).
The Vega system is interesting because it provides a snapshot of the early phase of planet formation.
If you want to make a "Star Trek" style tour of a system, landing on the planets and checking for the presence of life, you need to find a more "mature" system, where the planetary crusts have had time to cool off, and where most of the orbiting debris has alredy been swept up by planets.
One other interesting point about the Vega system though: It is bound to have an amazing number of large, highly visible comets ! In mature systems, most comets have either been kicked out to the Oort cloud or crashed into a planet.
Yours Birger Johansson Sweden
Re:Another thing to consider: (Score:3, Interesting)
I, for one, welcome our new Drake Equation [seti-inst.edu] overlords.
Sloppy definition of "Earthlike." (Score:5, Interesting)
By Earthlike I believe they mean terrestrial; a rocky world, as opposed to a gas giant.
Other known terrestrial worlds include baked-out Mercury, greenhouse-wracked Venus, and dry, cold Mars. Most people would not consider these "Earthlike" in the Star Trek Class M sense of the word.
That said: Even given the existence of terrestrial planets, Vega isn't a great place to go looking for a habitable, life-bearing world. It's a bright, hot star, which also means that it is a short-lived star. In a few hundred million years, when its potential planets begin to cool to the point where water would condense, Vega would be getting ready to wander off the main sequence and get way unpleasant to be near.
Another strike against life developing on Vega worlds: a greater percentage of its energy output would be in "bluer" wavelengths, including UV. Once it got started, life might adapt to UV, but to get started in the first place it needs some stability. I can see a influx of UV ripping apart delicate chemical chains in Vega Prime's oceans, greatly reducing the chance that life would get a foothold.
All this said, this is hopeful news, because the existence of one planet-forming debris field means there are probably others . . . some around more genial F and G and K class stars.
Stefan
Earth is a proper noun.. (Score:3, Interesting)
Re:to bad we're looking in the past (Score:4, Interesting)
They would probably be more interested in the political situation. They would be watching the throes of the Nixon impeachment crisis in the West, China would still be in the middle of the cultural revolution, Vietnam would have ended but only just. The USSR would be in mid collapse. Latin America is run by cliques of corrupt generals who murder tens of thousands (Pinochet) or hundreds of thousands (Argentina).
There has just been a war in the middle east. The Iranians are about to kick out the Shah (a brutal thug on a par with Saddam Hussein) and the Ayatolah would appear soon after to pervert the democratic revolution the same way Lenin appeared on the scene in Russia after the Tzar was deposed.
Things don't get any better for quite a while and they get worse before they get better. The nuclear arms race accelerates, the US and the USSR are engaged in a series of proxy wars that appear likely to turn nuclear. If you look at the situation from the outside even the events of 1989 might be considered evidence of further instability rather than a good sign.
On the whole I don't think that they are going to be avoiding talking to us just because of the disco music...
I think we should get our act together globally before we start to try to join extra-terrestrial clubs. If there is anyone out there worth talking to they already know about us.
Can this improve SETI's guessitude? (Score:2, Interesting)
Re:Probably not "finished" terrestrial planets yet (Score:1, Interesting)
Recent simulations [psc.edu] suggest that planets form in hundreds instead of millions of years.
Re:Another thing to consider: (Score:3, Interesting)
Those that *do* make it past that mass extinction filter (nuclear? bio? nano?), to Singularity [kurzweilai.net], are probably so far advanced as to be unrecognizable and uninterested in us primitive biological ants.
It's a pity humans still have all their eggs in one basket; until we've got self-sustaining offworld populations, we're a ticking time bomb.
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