The first alien world which has had its surface ‘mapped’ by astronomers

 

HELL has an address: 55 Cancri-e is the first alien planet to have some of its surface features directly observed. And it’s no tropical paradise.

For some time 55 Cancri-e has been considered ‘strange’. Some felt it may be made of diamond. Others suggested it was covered in exotic fluids.

So an international team of astronomers headed up by the University of Cambridge has examined data captured by NASA’s Spitzer Space Telescope about this 40-light-year distant ‘super-Earth’.

Orbiting a Sun-like star in the Cancer constellation, the astronomers observed the rocky planet through several entire orbits — each just 18 hours.

What they found is a world of extremes.

The planet is tidal-locked, meaning one face is permanently pointing towards the star.

This face is a sea of molten lava, with a surface temperature of 2400C

The ‘dark side’ is barely better.

It’s solid — but simmering at 1100C.

All this is odd: It shouldn’t be that hot, astronomers say, even though it does sit relatively close to its star.

They also found on out-of-place ‘hotspot’.

At about the halfway point between the point closest to the star and the night side is a bright streak.

The astronomers suggest this may be fast-flowing lava, behaving in a way very similar to that of water due to its extreme temperature.

“This shift either indicates some degree of heat recirculation confined to the day side, or points to surface features with extremely high temperatures, such as lava flows,” a statement reads.

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The data suggests a lava world where the lava becomes hardened on the dark side of the planet.

“The day side could possibly have rivers of lava and big pools of extremely hot magma, but we think the night side would have solidified lava flows like those found in Hawaii,” said Michael Gillon, University of Liège, Belgium.

55 Cancri e

55 Cancri-e’ is one of only a few rocky worlds close enough for detailed observation.

It also belong to a type of rocky ‘super-Earth’ planet that appears to be common, based on just a decade’s worth of discoveries of alien worlds.

“Our view of this planet keeps evolving,” says Brice Olivier Demory of the University of Cambridge, England, lead author of the report. “The latest findings tell us the planet has hot nights and significantly hotter days. This indicates the planet inefficiently transports heat around the planet. We propose this could be explained by an atmosphere that would exist only on the day side of the planet, or by lava flows at the planet surface.”

The study, published in the science journal Nature, details how astronomers used infra-red sensors to map the conditions on 55 Cancri-e’s rocky surface.

“By understanding the characteristics of the instrument — and using novel calibration techniques of a small region of a single pixel — we are attempting to eke out every bit of science possible from a detector that was not designed for this type of high-precision observation,” said Jessica Krick of NASA’s Spitzer Space Science Center, at the California Institute of Technology in Pasadena.