Thursday, May 17, 2007

This artist's concept shows the Neptune-sized extrasolar planet circling the star Gliese 436.
Image: images.cfm NASA.

A team of European and American astronomers say that a recently discovered extrasolar planet, located not far from Earth, contains oceans and rivers of hot solid water.

The team discovered the planet, Gliese 436 b, which is roughly the size of Neptune, using the Geneva Observatory and it is roughly 33 light-years away from Earth.

"The water is frozen by the pressure but it's hot. It's a bit strange -- we are used to water changing conditions because of temperature, but in fact water can also be solidified by pressure. It's not a very welcoming planet," said one of the astronomers who discovered the planet, Frederic Pont.

Scientists say that there is not likely to be any life on the planet, but that if there is such a large amount of water on it, then it is likely that other planets will also have water. It orbits closely around the Red M-dwarf star Gliese 436 which is significantly smaller and cooler than the Sun. The planet's surface temperature is believed to be near 540 degrees Fahrenheit (250 degrees Celsius). It circles Gliese 436 every 2.6 days at a small fraction of the distance between the Sun and Earth, or 4.1 million kilometers (2.6 million miles).

"It shows there are many ocean planets. From the size and the mass we get the density," added Pont who wrote in a report about the planet saying "the mass and radius that we measure for GJ 436b indicate that it is mainly composed of water ice. It is an 'ice giant' planet like Uranus and Neptune rather than a small-mass gas giant or a very heavy 'super-Earth."

American astronomers first discovered GJ 436b back in 2004, but no clear indication was found on what it might contain on its surface.

The same team of astronomers were made famous when they discovered the first "earth-like planet" Gliese 581 c in April.

Sources