Hubble Finds Massive Water World


Hubble has yet again managed to knock the ball out of the park, this time assisting scientists in finding an entire new class of planet. The planet GJ 1214b is pretty massive, somewhere between the mass of Uranus and Earth. But that’s not the important part:

Most of the planet is made from water.

GJ 1214b was discovered way back in 2009 by a ground based research team, rather than Kepler. It has a diameter 2.7 times that of earth, and has 7 times the mass. It orbits quite close to its dwarf star, but because of the dwarf star’s diminished output, its 38 hour day only gives it a surface temperature of 230 degrees Celsius. Which is hot, and is hot enough to boil water.

All that heat means that GJ 1214b has a thick, steamy atmosphere. Many would call it soupy, but that would probably be an understatement. But the enormous amounts of pressure means that there would be water somewhere down below, albeit far above the normal boiling temperature. Says team leader Zachory Berta,

“The high temperatures and high pressures would form exotic materials like ‘hot ice’ or ‘superfluid water’, substances that are completely alien to our everyday experience,”

The scientists believe that the planet started further out in the solar system, somewhere where water and ice could form naturally. But the planet had a decaying orbit, which eventually brought it as close is it is to its star. If that is true, then the planet will probably eventually enter the atmosphere of the star, evaporating all the water and destroying the planet.

But there’s another side to the results: we’ve found that water planets do likely occur in the universe. They happen at least frequently enough that our limited planet hunting ability has been able to find them. A good sign for the discovery of an earth-like planet in the near future.