Distant Super-Earth May Be Lit From Massive Volcanoes

| 5 May 2015 16:10

55 Cancri e, the "diamond planet" super-Earth, seems to be displaying massive temperature changes caused by countless volcanoes.

To most of us, the term "Super-Earth" sounds like something from a comic book, like if Krypton suddenly gained a yellow sun. But it's actually a real term astronomers use to describe 55 Cancri E, which has twice the diameter of Earth but eight times the mass. That gravity alone makes it an unpleasant place to live - for humans anyway - but scientists are also noticing drastic light and temperature changes. Over the past two years alone 55 Cancri e has appeared to swing from 1800 to 4900 degrees Fahrenheit, and insanely massive volcanoes are the most likely cause.

"This is the first time we've seen such drastic changes in light emitted from an exoplanet, which is particularly remarkable for a super-Earth," Dr. Nikku Madhusudhan of Cambridge's Institute of Astronomy explained. "No signature of thermal emissions or surface activity has ever been detected for any other super Earth to date."

55 Cancri e is a fairly well-known and observed planet. When it was first discovered it was believed to be a carbon-rich world, prompting it to be dubbed the "diamond planet". But it's bizarre in other ways as well - 55 Cancri e is uncomfortably close to its sun, where a single year lasts 18 days. Add that one side of this large planet always faces the sun, and the planet's crust is probably weakened. If true, that means volcanoes would be incredibly common and the oceans are probably made of magma.

"While we can't be entirely sure," Brice-Olivier Demory of the University of Cambridge explained, "we think a likely explanation for this variability is large-scale surface activity, possibly volcanism."

What's especially impressive about these findings isn't that the planet is perpetually erupting - it's that we could peek through the atmosphere to judge its temperature. Mapping the surface temperatures of planets can be difficult, and gas giants are much easier to study because of their size. It certainly doesn't help that 55 Cancri e's volanic plumes could effect the results - perhaps even creating the huge temperature variability we've been seeing. As it stands, this is a huge step to understanding what distant planets might be like - even if we shouldn't visit this one in particular.

Source: University of Cambridge, via Discovery News

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