poopee Wrote:First 'habitable' exoplanet confirmed
Tuesday, 17 May 2011
Agence France-Presse
Gliese 581d

Gliese 581d is the outlying planet in the Gliese 581 system, and orbits its parent star every 66.8 days. It may be covered by a large and deep ocean and is the first serious 'waterworld' candidate discovered beyond our Solar System.

Credit: ESO/L. Calçada

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PARIS: A rocky world orbiting a nearby star was confirmed as the first planet outside our Solar System to meet key requirements for sustaining life.

Modelling of planet Gliese 581d shows it has the potential to be warm and wet enough to nurture Earth-like life, scientists have said. It orbits a red dwarf star called Gliese 581, located around 20 light years from Earth, which makes it one of our closest neighbours.

Gliese 581d orbits on the outer fringes of the star's 'Goldilocks zone', where it is not so hot that water boils away, nor so cold that water is perpetually frozen. Instead, the temperature is just right for water to exist in liquid form.

Zarmina's World

"With a dense carbon dioxide atmosphere - a likely scenario on such a large planet - the climate of Gliese 581d is not only stable against collapse but warm enough to have oceans, clouds and rainfall," France's National Centre for Scientific Research (CNRS) said.

More than 500 planets orbiting other stars have been recorded since 1995, detected mostly by a tiny wobble in stellar light. Exoplanets are named after their star and listed alphabetically, in order of discovery.

Until now, the big interest in Gliese 581's roster of planets focussed on Gliese 581g. It leapt into the headlines last year as 'Zarmina's World', after its observers announced it had roughly the same mass as Earth's and was also close to the Goldilocks zone.

No doubt that it exists

But that discovery has since been discounted by many. Indeed, some experts suspect that the Gliese 581g may not even exist but was simply a hiccup in starlight.

Its big brother, Gliese 581d, has a mass at least seven times that of Earth and is about twice our planet's size, according to the new study, which appears in a British publication, The Astrophysical Journal Letters.

The planet, spotted in 2007, had initially been dismissed as a candidate in the hunt for life. It receives less than a third of the solar radiation Earth gets, and may be "tidally locked", meaning that one side of it always faces the Sun, which would give it permanent dayside and nightside.

300,000 years to get there

But the new model, devised by CNRS climate scientists Robin Wordsworth, Francois Forget and colleagues, showed surprising potential. Its atmosphere would store heat well, thanks to its dense CO2, a greenhouse gas. And the red light from the star would also penetrate the atmosphere and warm the surface.

"In all cases, the temperatures allow for the presence of liquid water on the surface," said the researchers.

For budding travellers, though, Gliese 581d would "still be a pretty strange place to visit", the CNRS said. "The denser air and thick clouds would keep the surface in a perpetual murky red twilight, and its large mass means that surface gravity would be around double that on Earth."

Getting to the planet would still require a sci-fi breakthrough in travel for earthlings. A spaceship travelling close to light speed would take more than 20 years to get there, while our present rocket technology would take 300,000 years.

However, humanity has already tried to make contact with the new planet. During Australia's National Science Week in August 2009, Cosmos magazine partnered with the Australian government, NASA and the CSIRO to run a 13-day campaign to collect goodwill messages from the public to be sent to Gliese 581d.

The initiative, known as Hello From Earth, collected 26,000 messages, which were transmitted by NASA's Tidbinbilla facility. The signal is not due to arrive until January 2030.

Alley Wrote:http://www.hellofromearth.net/ In 2009, messages were gathered from the public to send to the newly found planet. Some of the messages are pretty funny, some are touching. Check them out.

Mute Wrote:I never understood what point there was to sending these sorts of messages. Do people expect aliens to understand whatever language that's presented on the thing? I mean really, that's just silly.

But hey maybe if NASA / financial backers / the scientific community get off their collective asses, we could finally begin planning ways to get there.

Sarah Wrote:I would love to see something like this but I have no faith humanity will ever make it off earth to another habitable planet. Really, short of some alien colony coming to earth and providing us with advanced tools, there's little chance of anything decent ever happening. It's a shame that the universe is so big yet we can't do pomegranate in it.

Alley Wrote:If humanity can overcome it's diversity and live in peace(slim chance), there is no doubt in my, or Carl Sagan's mind, that we will one day be able to travel through the cosmos efficiently and to the point that we will be able to contact other life forms. I cross my fingers and wish on a star that my ancestors will one day get the privilege to do so.

Mute Wrote:Nah we just need the rich white men to stop trying to stroke their own wealthy egos and get in on the galactic circle jerk of space exploration and colonization.

Alley Wrote:But we don't have the technology to even fathom of making a journey of quarter of the distance, let alone the full 300,000 years it will take us.

Alex123123 Wrote:-Incoherent blabber -

Eh. Humanity WILL be able to travel outside the solar system. It's just a matter of time. Really, only thing that would prevent humanity from doing so is total extinction, which is highly unlikely unless:

Someone develops Foxdie. Or we get hit by two asteroids in opposite sides of the planet.
Or black holes. Or instant atmospheric collapse. Or we never improve technology for the following billions years, and then the sun goes supernova and fries our collective asses (while cosplaying as Sephiroths (totally worth it.) )

-More incoherent blabber-

But man, it would be cool as hell to see the first few bigass ships housing entire civilizations just randomly traveling space. Macross style. W/o the mechas... probably.

pineapple, I wanted to be born later in the future.
Someone better clone me! AND my memories!

-On topic.-
Hell yeah!

Alley Wrote:Imagine the space ship that was on Wall-E. Would look very badass.

Alex123123 Wrote:and then the sun goes supernova and fries our collective asses