NASA Telescope Finds a ‘Water World’

Observations by NASA’s Hubble Space Telescope have added a new type of planet to the mix. By analyzing the previously discovered world GJ1214b, astronomer Zachory Berta (Harvard-Smithsonian Center for Astrophysics) and colleagues proved that it is a waterworld enshrouded by a thick, steamy atmosphere.

GJ1214b was discovered in 2009 by the ground-based MEarth (pronounced “mirth”) Project, which is led by CfA’s David Charbonneau. This super-Earth is about 2.7 times Earth’s diameter and weighs almost 7 times as much. It orbits a red-dwarf star every 38 hours at a distance of 1.3 million miles, giving it an estimated temperature of 450 ° Fahrenheit.

In 2010, CfA scientist Jacob Bean and colleagues reported that they had measured the atmosphere of GJ1214b, finding it likely that the atmosphere was composed mainly of water. However, their observations could also be explained by the presence of a world-wide haze in GJ1214b’s atmosphere.

Berta and his co-authors used Hubble’s WFC3 instrument to study GJ1214b when it crossed in front of its host star. During such a transit, the star’s light is filtered through the planet’s atmosphere, giving clues to the mix of gases.

GJ1214b has much more water than Earth, and much less rock. As a result, the internal structure of GJ1214b would be very different than our world. A paper reporting these results has been accepted for publication in The Astrophysical Journal and is available online.

Source: Digg

Image: Current