An "Earth-Like" new world discovered?

I think they might really be stretching the meaning of "earth-like".

From the British Daily Mail online:
Found 20 light years away: the New Earth

[...] "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life."

Gliese 581 is among the closest stars to us, just 20.5 light years away (about 120 trillion miles) in the constellation Libra. It is so dim it can be seen only with a good telescope.

[...]

It has a mass five times that of Earth, probably made of the same sort of rock as makes up our world and with enough gravity to hold a substantial atmosphere.

Astrobiologists - scientists who study the possibility of alien life - refer to a climate known as the Goldilocks Zone, where it is not so cold that water freezes and not so hot that it boils, but where it can lie on the planet's surface as a liquid.

[...]

The surface gravity is probably around twice that of the Earth and the atmosphere could be similar to ours.

Although the new planet is in itself very Earth-like, its solar system is about as alien as could be imagined. The star at the centre - Gliese 581 - is small and dim, only about a third the size of our Sun and about 50 times cooler.

The two other planets are huge, Neptune-sized worlds called Gliese 581b and d (there is no "a", to avoid confusion with the star itself).

The Earth-like planet orbits its sun at a distance of only six million miles or so (our Sun is 93 million miles away), travelling so fast that its "year" only lasts 13 of our days.

The parent star would dominate the view from the surface - a huge red ball of fire that must be a spectacular sight.

It is difficult to speculate what - if any - life there is on the planet. If there is life there it would have to cope with the higher gravity and solar radiation from its sun.


Just because Gliese 581c is habitable does not mean that it is inhabited, but we do know its sun is an ancient star - in fact, it is one of the oldest stars in the galaxy, and extremely stable. If there is life, it has had many billions of years to evolve.

This makes this planet a prime target in the search for life. According to Seth Shostak, of the Search for Extraterrestrial Intelligence Institute in California, the Gliese system is now a prime target for a radio search. 'We had actually looked at this system before but only for a few minutes. We heard nothing, but now we must look again.'

By 2020 at least one space telescope should be in orbit, with the capability of detecting signs of life on planets orbiting nearby stars. If oxygen or methane (tell-tale biological gases) are found in Gliese 581c's atmosphere, this would be good circumstantial evidence for life.

Dr Malcolm Fridlund, a European Space Agency scientist, said the discovery of Gliese 581c was "an important step" on the road to finding life. [...]

The article is full of all sorts of details. The scientists are speculating a lot though; speculating is not facts. Still, some of their educated guesses are interesting, and the data they can collect does present a lot of possibilities.

While the planet isn't truly like earth, it may be earth-like in the sense that it comes closer to being like earth than any other planet we've been able to detect.

As technology advances, I'm sure we will be able to observe more, even from such a far distance. But to really find things out, we'll have to go there. And that, I expect, is a long ways off!