spaceSpace and Physics

This Weird Super-Earth Has An Atmosphere Similar To Ours


Jonathan O'Callaghan

Senior Staff Writer

Artist's impression of 55 Cancri e. NASA/JPL-Caltech

The super-Earth 55 Cancri e, at first glance, doesn’t look anything like our planet. It’s twice as big and orbits extremely close to its star, with intense lava flows on the surface.

But in a surprising finding, scientists say that this strange world actually has an atmosphere that’s very similar to ours. The research was published in The Astronomical Journal.


"If there is lava on this planet, it would need to cover the entire surface," said Renyu Hu from NASA's Jet Propulsion Laboratory in Pasadena, California, a co-author on the study, in a statement. "But the lava would be hidden from our view by the thick atmosphere."

The planet, located 40 light-years from us, orbits its star at a distance of just 0.016 AU (astronomical units, 1 AU is the distance from Earth to the Sun).

At this distance, its year lasts just 18 hours, and the planet is extremely hot and not habitable for life as we know it. It is tidally locked to its star, which means one side always faces the star. The hot side averages 2,300°C (4,200°F), but the cold side isn’t much better at up to 1,400°C (2,600°F).

Using NASA’s Spitzer Space Telescope in 2016, researchers found that lava in lakes on the day side would flow to the night side, where they harden.


However, taking a look at the planet again, they found that despite these unusual characteristics, the planet is likely to have an atmosphere with similar ingredients to ours, but much thicker. It’s thought to contain nitrogen, water, and even oxygen.

They came to this conclusion by looking at the light reflected by the planet. The changes in brightness seen, according to the researchers, is best explained by Earth-like atmospheric ingredients.

The planet even has a similar density to Earth too, so it might be rocky as well – some even suggested the planet was made of diamond, although that theory has been quashed somewhat.

This new research, though, opens up a lot of questions. Why is the atmosphere similar to ours, and why hasn’t the planet’s proximity to its star caused its atmosphere to be blown away?


Understanding this may tell us more about rocky planets in the universe. One thing’s for sure though, no matter how weird a planet looks, you can find some surprisingly Earth-like features.


spaceSpace and Physics
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