Topic: Earth-like planets in our galactic neighborhood

[sam]

well, doh!

http://www.google.com/hostednews/afp/article/ALeqM5jBAjRb67zrOUulZ6TLCFOXvhq8LQ

CHICAGO (AFP) — Earth-like planets with life-sustaining conditions are spinning around stars in our galactic neighborhood, US astrophysicists say. They just haven't been found yet.

"There are something like a few dozen solar-type stars within something like 30 light years of the sun, and I would think that a good number of those -- perhaps half of them have Earth-like planets," Alan Boss told the annual meeting of the American Association for the Advancement of Science (AASS).

"So I think there is a very good chance that we will find some Earth-like planets within 10, 20 or 30 light years of the Sun," the astrophysicist from the Carnegie Institution for Science told his AAAS colleagues meeting here since Thursday.

One light year equals the distance light travels in one year at the speed of 300,000 kilometers (186,000 miles) per second, or 9.46 trillion kilometers (5.88 trillion miles).

Boss is convinced that the Earth-sized planets could be found either by the Kepler space telescope US space agency NASA plans to launch on March 5, or by the French-European telescope-equipped COROT satellite that has been in orbit since 2006.

"I will be absolutely astonished if Kepler or COROT didn't find any earth-like planets, because basically we are finding them already," Boss told a press conference Saturday when asked why he felt so confident.

COROT has already discovered the smallest extraterrestrial planet so far. At a little over twice the Earth's diameter, the planet is very close to its star and very hot, astronomers reported earlier this month.

Boss said Kepler and COROT will likely find so many Earth-like planets that they will "tell us how to go ahead and build the next space telescope to go and examine these planets, after we know they are there."

The images from those new planets, he added, should identify "light from their atmosphere and tell us if they have perhaps methane and oxygen. That will be pretty strong proof they are not only habitable but actually are inhabited."

"I am not talking about a planet with intelligence on it. I simply say if you have a habitable world ... sitting there, with the right temperature with water for a billion years, something is going to come out of it.

"At least we will have microbes," said Boss.

Raymond Jeanloz, professor of astronomy, earth and planetary science at the University of California at Berkeley, delved further into the matter.

"I can strongly reinforce Alan Boss's point that life from this perspective that is very much driven by our understanding from the genome, is in some sense 'inevitable,'" if the same basic building blocks of life that exist on Earth are present.

"The distinction will be more between a class of life form that can communicate with us versus ... the vast abundance of life forms recorded in our fossil records, namely microbial life."

On the possibility of finding an extra-terrestrial civilization, Boss said the research "is an interesting one and an important one to do because, even though there is a small probability of success, if you actually find something, it is an immense discovery to make.

"So you say, 'yes, this is worth doing.'"

[Simon]

I find it impossible to believe that we are the only life form in the whole of everything. 

[sam]

same here... just got to find it..

[Simon]

... or they find us.  Trouble is, if they did, the Americans would shoot them down!

[sam]

maybe they already have.

I'm convinced we won't find bipeds... I'd be happy with bacteria.

[Simon]

Well, that's how we started, so what's to say there isn't a planet with the same conditions as ours somewhere, with a similar evolution?

[Rik]

It always seems to me that, statistically, there has to be a planet with a similarly evolved lifeform. Whether it's a way of explaining deja vu is another matter.

[sam]

yeah, if they have evolved like us then they probably nuked each other already.

Actually, going on current numbers we don't know of many planets that could host life - and there aren't that many stars that have the so called goldilocks zone around them. As soon as you start getting closer to the galactic centre the background radiation from other stars also starts to become a problem. Its actually quite an interesting field in the statistically sense, but still given all these things we would expect to find 10s of lifeforms similar to our own in the galaxy - however they are probably too far away for any sort of contact or observations.

[Camstop]

2 billion stars in the milky way, the closest galaxy 4 times the size of the milky way and billions of galaxy's 

There must be millions of solar systems and maybe loads with more than one inhabited planet. I also expect there will be other planets that have evolved much quicker and we may be no better than average if that.

We hardly know what's going on on Mars never mind anything else 

Also as earthlings we are like gremlins, greedy and selfish on the whole and i'm sure other solar systems especially where there is more than one inhabited planet may be far more advanced.

There's also nothing to say the important people on earth aren't aliens 

[sam]

We hardly know what's going on on Mars never mind anything else

We actually know quite a lot about Mars - apart from the fine surface detail - but we definitely know more about surface of Mars than the Earth's ocean floors.

A very simple approximation can be done with the Drake Equation which gives out rather depressing numbers, http://www.pbs.org/wgbh/nova/origins/drake.html  - it is probably slightly higher but not that high either.

Also if you look at the current list of exoplanets, http://exoplanet.eu/catalog-all.php, you see that there aren't many systems detected so far that are like our own. Of course we have selection effects to include in there, but there are still a large number of highly eccentric orbits there - which is nothing like what we see for the planets in our solar system.