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The rare super-Earth made of diamond
40 light years away, astronomers have found a jewel of a planet
Roughly one-third of 55 Cancri e's mass comes from diamonds.
Roughly one-third of 55 Cancri e's mass comes from diamonds.
NASA/JPL-Caltech
C

an you say "bling bling?" Stargazing scientists at Yale can. They've discovered a rare super-Earth that approximates our planet's mass and radius, except for one big difference: Unlike our water-based planet, this one's made largely out of diamond. The world, inelegantly named 55 Cancri e, was first discovered in 2004, but it's only now that researchers have pinned down its diamond make-up. Here's what you need to know about the sparkly, strange new world:

Where is it?
The diamond planet is located a mere 40 light years from Earth. It orbits a binary star, 55 Cancri, alongside a handful of other planets. The star itself is so close "it is visible to the naked eye in the night sky," says Clara Moskowitz at Space.com. The diamond planet is a little bit bigger than Earth, with twice the radius and, due to its density, eight times the mass.

Why is it made out of diamonds?
The star system is primarily made of carbon, iron, and silicon, and over millions of years, 55 Cancri e's pressure and heat turned the planet's carbon mantle into diamond, says Sebastian Anthony at ExtremeTech. Yale researchers estimate that roughly a third of the planet's mass is made of pure diamond. That adds up to "a few trillion times more diamond than has ever been mined on Earth" — or a lot of wedding rings. 

What's it like there?
With surface temperatures reaching 3,900 degrees Fahrenheit, the planet is probably unfit for life (or at least life as we know it). While previous studies posited that the planet has "supercritical fluids," new findings suggest it contains no water at all. And all that diamond could lead to "very different thermal evolution and plate tectonics processes than Earth," says Space.com's Moskowitz, "which could create bizarre types of volcanism, seismic activity, and mountain formation."

Is this new diamond world one of a kind?
Nope. A diamond planet roughly five times larger than Earth was discovered by Australian astronomers in 2011, about 4,000 light years away in the Serpens constellation. But unlike that discovery, 55 Cancri e is the first to orbit a sun-like star — and it might not even be the weirdest planetary possibility out there, says David Spergel, an astronomer at Princeton University. "The 'diamond-rich super-Earth' is likely just one example of the rich set of discoveries that await us as we begin to explore planets around nearby stars."

Sources: ExtremeTech, Reuters, Space.com

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