Earth-like planet discovered

[Sparrowhawk]

http://www.cnn.com/2007/TECH/space/04/2 ... topstories

• Astronomers detect exoplanet with possible Earth-like temperatures
• Planet orbits a red dwarf star called Gliese 581
• Gliese 581 is 20.5 light-years away in the constellation Libra
• Scientist: Earth-like planet is either rocky or covered with oceans

http://space.newscientist.com/article/d ... -life.html

(newscientist.com links take a little while to actually come online sometimes)

[jotabe]

I couldn't help think of this...
http://www.worlddreambank.org/L/LYR.HTM

[Fish Tank]

Read a similar article said something like it would take 23 million years to get there with our current technology.

[Slim]

The article I read pointed out that Mars also fits the same parameters for life as this planet - Earth similar masses and temperatures.

But, yeah, I think that's really cool all the same.

[Seiryu]

If the planet larger than earth, wouldn't it have gravity that would make it hard for us to walk about?

[eriador]

Depends on the density, but probably yes.

[Seiryu]

I guess the planet in question has a low density? I mean, not too low, otherwise there'd be no atmosphere and not much gravity, but if they think it's a possibility, the density for its size has to be low.

But then again, do they know that?

[Dr. Mobius]

Educated guesses. It would be impossible to be sure without sending someone/thing there to confirm it, but as that would take too long we're left with the tools we have available. We have a pretty good idea what Earth looks like from space so we look for objects that give off a similar signal. It's not a perfect system by far, but it'll do until something better comes along. Besides, it's not like we'll be visiting any of these rocks anytime soon anyways.

[jotabe]

If it is a rocky planet, density would be the same as the Earth, roughly. So, even with a larger mass, the surface would be at a longer distance from the planet mass center.
Still, mass grows cubicly with the radium, so there would be a large increase of our weight on surface, assuming same density. But it wouldn't be linear with the increase of the planet mass.

Edit:
A rocky planet larger than Earth would gather a bigger atmosphere, effectively reducing the planet's density (think of the gas giants: their rocky nucleus is probably larger than Earth).

Also, having in account that we have a larger atmosphere, the pressure on surface would be larger too, what means gas on surface would be pretty dense (hydrostatic equilibrium conditions). Denser gas means that the "effective weight" of a body on the surface would be less than the weight in absence of atmosphere (Archimedes Principle).
So, it might be possible that the weight we perceive for ourselves on the surface of that planet wouldn't be as large as we could expect.

[Dr. Mobius]

Woah, according to the time stamp, I just posted that a week ago. But it feels like it should be much longer, at lease a month or so.

My mind is going, Dave...