30 September 2010

Even more fascinating Exoplanet news

Back in 2007 I put up a post about the discovery of an exoplanet Gliese 581c. At the time it was one of three planets discovered around the red dwarf star Gliese 581c which is just 20 light years from earth ( Just down the road in astronomical terms but for the foreseeable future it may as well be on the other side of the universe in terms of getting up close and personal).

Gliese 581c is close to the star’s so called Goldilocks zone (aka the Habitable Zone or HZ - the band around a star where water can exist in liquid form and thus amenable to life…. or at least life that may be remotely earth-like). At the time it was the smallest know extra solar planet was considered a possible location of extrasolar life.

Gliese 581 seems to be a goldmine for exoplanets: In 2009, 581d, a “super-earth” was found to be in the HZ; 581e, although beyond the HZ is at 1.9 times the mass of the earth the smallest exoplanet so far.

And there’s more!

According to today’s Guardian there is yet another planet , Gliese 581g , which is potentially habitable (being in the HZ) and of a similar size to Earth.

Gliese 581g, has a mass of three to four times that of Earth and takes 37 days to orbit the star. Astronomers believe it is a rocky planet with enough gravity to retain an atmosphere.

One side of the planet is always facing the star, much as one side of the moon constantly faces Earth. This means that the far side of the planet is constantly in darkness. The most habitable region of the planet would be the line between the light and dark regions.

The average temperature on the planet is estimated to be between -31 to -12C, but the ground temperature would vary from blazing hot on the bright side and freezing on the dark side.

"Our findings offer a very compelling case for a potentially habitable planet," said Steven Vogt, an astronomer at the University of California, Santa Cruz. "The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common."

"The number of systems with potentially habitable planets is probably on the order of 10 or 20 percent, and when you multiply that by the hundreds of billions of stars in the Milky Way, that's a large number. There could be tens of billions of these systems in our galaxy,"

This is utterly fascinating stuff. I can imagine that such discoveries will be come more and more commonplace.. I can only imagine what newer and more advanced telescopes will reveal.

Shame that we will never see them in the flesh though


Steve Bates said...

"Shame that we will never see them in the flesh though"

Just don't be in the neighborhood when d and g collide someday!

jams o donnell said...

I will make sure I am not Steve!

Andrew Scott said...

Actually Jams, I have obtained from some of my exotic "friends" a nifty if rather old superluminal-hyperdrive capsule. It has done over 1 billion light years, the previous owners have not been at all careful, the solar shock absorbers have gone and the quantum clutch is wearing thin, but with luck it could get us there in a few months (but not back). There is room for only ten on board. Who is up for coming along with me for a new start? We need some genetically "proven" old men and some fertile young women. Could be fun (for the old men at least). If there are no other volunteers I'll selflessly do the old man tasks all by myself. I don't think we'll have an internet connection though, so when my own blog stops you'll know where I've gone. I've told my wife and she says "Fine, just leave your wallet and online banking passwords when you go." Sweet.

jams o donnell said...

Andrew Brilliant, I'm with you on that one. I'll pack my bag and stop the milk. The not-wife doesn't mind, she is happy to get the whole bed and not listen to me snoring!

susan said...

It's common for people to think of earth-like planets as being potentially habitable for people but the fact is if there is life on a planet in a habitable zone it would more than likely have a biology quite different from ours. So we may be stuck even with the superluminal hyperdrive capsule. Or this may be sour grapes because I'm an older woman and not invited anyway.

Andrew Scott said...

Truth is I don't care about its habitability Susan, I'm just wanting to enjoy the few months on the way out. Men, don't you know... they will promise a girl the world (or a world), but will rarely deliver on the promise.

jams o donnell said...

Ah Susan I'm sure we could change the arangements!

Ah the ultimate cruise Andrew? I bet you were going to tell the girls they would go toe heavens and back instead of just the heavens!

Andrew Scott said...

The Earth will move, away from them.

jams o donnell said...

Absolutely.. About the only way I could make the earth move for a lady these days, earthquake machines aside!

Stan said...

It's a very interesting discovery, despite the hype. There's an excellent article about it in Seed magazine.

jams o donnell said...

Definitely! In not so many years I am sure it will be a commonplace event though. Thanks for the link to Seed Magazine. Not heard of it before