US discover new planet GJ1214b dubbed 'super-Earth'
- From: AFP
- February 22, 2012
- Researchers confirm planet GJ1214b is a 'super-Earth
- Planet is "a waterworld with a thick, steamy atmosphere"
- It is about 2.7 times Earth's diameter
AN astronaut attempting to visit recently discovered planet GJ1214b would land in hot water - literally, US scientists say.
Researchers at the Harvard-Smithsonian Centre for Astrophysics said they have identified an entirely new kind of planet, dominated not by rock, gas or other common materials, but water.
The planet is "a waterworld enshrouded by a thick, steamy atmosphere", they said in a statement, after scrutinising the planet with NASA's Hubble Space Telescope.
"GJ1214b is like no planet we know of," astronomer Zachary Berta said. "A huge fraction of its mass is made up of water."
GJ1214b was discovered in 2009 by the ground-based MEarth Project. Described as a "super-Earth", it is about 2.7 times Earth's diameter and weighs almost seven times as much.
Further studies in 2010 led to scientists suspecting that the planet, where the temperature is some 232 Celsius, was largely covered in water. This was confirmed by Mr Berta and his co-authors using Hubble to study the planet when it crossed in front of its host star.
The light of the star, filtered through the planet's atmosphere, gave clues to the mix of gasses, backing up the water vapour theory.
"The Hubble measurements really tip the balance in favour of a steamy atmosphere," Mr Berta said.
Further measurements and estimates led scientists to conclude that the planet has much more water than Earth and much less rock. That, together with high temperatures and pressure, likely produce some highly exotic results, including "hot ice", scientists say.
Our solar system contains three basic planet types: rocky, like Earth; gas giants like Jupiter or Saturn; and ice giants like Uranus.