Scientists think they've found a planet with a core of diamond

Contributed by
Jan 22, 2013, 5:53 PM EST

A while back we told you about the discovery of a former star that had basically formed into a huge, planet-sized diamond. Now scientists think they've found another cosmic body with a thick diamond core, and it's only 40 light-years away.

For some time now, astronomers and astrophysicists have been looking at the possibility that many planets in our universe could be made primarily of carbon. Though it's a major part of organic life here on Earth, and is the basis for things like oil and coal, Earth itself is actually less than 0.1 percent carbon, and most of the rock on our planet is made up of oxygen-based materials. That's thanks, in part, to how our solar system formed. Back before the planets came together, the cloud of dust and gas that would eventually become our home contained about twice as much oxygen as carbon.

But that's not the case with other stars and planets. Consider 55 Cancri e, a planet with about twice Earth's diameter and nearly eight times Earth's mass orbiting the star 55 Cancri A in the constellation Cancer. Though it was first discovered back in 2004, until recently scientists hadn't been able to determine what exactly 55 Cancri e was made of. Now they're pretty sure it's carbon, and given the heat and pressure present inside a planet of its size, they're also pretty sure that the planet's core is pure diamond.

"As you go beneath (the thick graphite crust of the planet), you see a thick layer of diamond," said astrophysicist Nikku Madhusudhan, a postdoctoral fellow at Yale University.

So how did 55 Cancri e wind up this way? Madhusudhan in his colleagues believe it has a lot to do with the planet's host star, which contains more carbon than oxygen. If this was also true when the planet formed, it would explain why carbon became the dominant material.

But apart from its bling-tastic center, what else could 55 Cancri e have to offer? Could anything live on it? Maybe, but whatever lifeforms a carbon-based planet contained would be very different from us. They'd likely use oxygen as fuel in the same way we use oil and coal, and those big chunks of compressed carbon that we covet (diamonds) would be far less valuable to them.

"You would not be impressed if someone gave you a diamond ring," said Marc Kuchner of NASA's Goddard Space Flight Center. "If your suitor showed up with a glass of water, that would be really exciting."

(Via Scientific American)

Make Your Inbox Important

Like Comic-Con. Except every week in your inbox.

Sign-up breaker