Discovery of two exoplanets mainly made of water

Discovery of two exoplanets mainly made of water

By studying data from two telescopes of the Nasa, Hubble and Spitzer, researchers from the University of Montreal have discovered two exoplanets which would be covered with water, reports the HuffPost. Their discovery was published this Thursday in the journal Nature Astronomy.

These two planets are very far from Earth. They are 218 light-years apart and are located in the constellation of Lyra. They revolve around a dwarf star called Kepler-138, smaller than our sun, according to statement released by NASA. The name of these exoplanets is derived from their sun, either Kepler-138c and Kepler-138d, but scientists also call them “aquatic worlds”.

The presence of water is deduced

The presence ofwater on these two exoplanets cannot be attested by means of the instruments at our disposal, but deduced. By studying the mass and size of the two planets, the scientists estimated that 50% of their volume must be “made up of materials lighter than rock but heavier than hydrogen or helium”. The most likely material in such a case is water, says NASA.

“We previously thought that planets a little larger than the Earth were large balls of metal and rock, like enlarged versions of the Earth,” says Björn Benneke, co-author of the study and professor of astrophysics at the University of Montreal. “However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature, and that a large part of their total volume is probably made up of water,” he adds.

We already knew that three planets revolve around Kepler-138. But a fourth has just been discovered by the two telescopes and it promises great revelations. Named Kepler-138e, it would be located in a so-called “habitable” zone. This means that it could also harbor water and that life is likely to develop there, unlike its two neighbours.