Exoplanet Explorer: WASP 12b

Imagine you’re a poor, helpless planet orbiting a normal yellow dwarf star, a star not so dissimilar to our own Sun. But that star keeps drawing you closer and closer… and closer. You know this could end badly for you, but you cannot resist. Soon, it’s too late. Like the monster from Stephen King’s It, the star is going to eat you alive.

Such is the fate of WASP 12b, an exoplanet discovered in 2008 by the SuperWASP planetary transit survey. Wasp 12b is a carbon rich planet, with an atmosphere of mostly methane and carbon monoxide, and astronomers suspect the planet’s core might be made of graphite and diamond.

You could describe WASP 12b as a hot Jupiter, a gas giant that’s strayed perilously close to its parent star. WASP 12b is also sometimes referred to as a chthonian planet, though in my opinion that seems a bit premature. The planet appears to be in its final death throes, so to speak, but it’s not quite dead yet.

In 2010, observations by the Hubble Space Telescope revealed that the planet’s atmosphere is being stripped away, with streams of matter falling toward the star to be “consumed.” Eventually all that will remain of WASP 12b is its core. At that point, I think the term chthonian planet will be appropriate.

That is assuming, of course, that anything will remain at all. Given how violently WASP 12b is being destroyed, it’s possible even that diamond core will be ripped apart and devoured. According to current estimates, we’ll have to wait about 10 million years to find out—a surprisingly short period of time in the cosmic scheme of things.

P.S.: To my surprise, WASP 12b has started making headlines just in the last few days. Astronomers recently determined the planet is incredibly dark in color, almost pitch black. That seemed strange to me at first, but I guess if you’re going to have a planet with that much carbon, the dark coloration kind of makes sense.