The Search for More Earths

[Sir Ulli]

Summary: When astronomers first realized that the stars in the sky were like our Sun, only more distant, they wondered if those stars had planets too. And if they have planets, is there life? Intelligent life? There's an answer - yes or no - but we don't know it yet. NASA and the European Space Agency are working on a series of space and ground-based observatories that may help get an answer soon. In just a decade, you could gaze into the night sky, locate a star, and know that there's life there. Life could be everywhere.

Scene from a moon orbiting the extra-solar planet in orbit around the star HD70642.
Credit: David A. Hardy, astroart.org (c) pparc.ac.uk


Until a decade ago, astronomers weren't even sure there were any planets outside the Solar System. You'd be hard-pressed to find anyone who believed we had the only planets in the entire Universe, but we still didn't have any direct evidence they existed. That all changed in October 5, 1995 when Michel Mayor and Didier Queloz announced they had discovered a planet half the mass of Jupiter orbiting furiously around a star called 51 Pegasi. The discoveries came fast; at last count, there are 122 confirmed extrasolar planets.

But these extrasolar systems generally look nothing like our own Solar System. Many contain massive planets which orbit extremely close to their parent star; no chance for life there. Planets roughly the size and orbit of Jupiter have been uncovered, but it's impossible for the current technology to see anything the size of our own Earth.

Fortunately, there's a series of ground and space-based observatories in the works that should be capable of detecting Earth-sized planets around other stars. NASA and the ESA are working towards the goal of being able to directly photograph these planets and measure the composition of their atmospheres. Find large amounts of oxygen, and you've found life.

Missions on the way


Corot 2006

Kepler 2007

Space Interferometry Mission 2009

Terrestrial Planet Finder 2012-2015

Darwin 2014

get the Full and interesting Strory at Astrobiology Magazine

Sir Ulli

 

[ozzlo]

yet another great read, thank you

ozzlo

 

[daba]

Berkeley rocks. SETI has a huge payoff. Thanks for the information.

 

[orthus]

The ground based portion almost took a major hit though. Luckily the LBT on Mt Graham was spared, having come within a few hundred feet of going up in flames due to those wildfires.

 

[theELVISCERATOR]

the fact that the chances of another earth in a universe so large gives one pause doesnt it?

Any number of small changes in our planets "biology" would render this planet as dead as every other thing in the night sky we have seen so far.

 

[TC]

Any number of small changes in our planets "biology" would render this planet as dead as every other thing in the night sky we have seen so far.

Or perhaps just vastly different from the status quo. It looks as though life is probably more the norm than not, given the fact that it exists in some of the most inhospitable places on our planet. It seems life is almost bound to happen given the even the slightest opportunity. So far we've only been able to take a limited look at our local solar system, but I suspect as soon as we're able to reach out we may be very surprised at how many neighbors we have, albeit in whatever shape, form, and chemical composition they may be.

 

[katelin]

Or perhaps just vastly different from the status quo. It looks as though life is probably more the norm than not, given the fact that it exists in some of the most inhospitable places on our planet. It seems life is almost bound to happen given the even the slightest opportunity. So far we've only been able to take a limited look at our local solar system, but I suspect as soon as we're able to reach out we may be very surprised at how many neighbors we have, albeit in whatever shape, form, and chemical composition they may be.

I agree with you TC.

I seem to remember reading or seeing a documentary about the origin of life. I think it said that life on earth happened by pure chance, on just the right combinations of chemical reactions sparked at the right time by lightning to create the first primitive cell. And that life on earth could have easily never happened at all. If so then life in the universe is extremely rare. And it's quite possible that we (earth) are the only life in the universe.

Can you think of anything more grim than that? I think what you said makes more sense.