A team of astronomers has found evidence that two of the exoplanets orbiting the red star are “water worlds,” that is, planets with water making up a large part of their volume, according to a report by RT.
These two watery worlds, unlike any planets we see in our solar system, are located in a planetary system 218 years from Earth in the constellation Lyre.
These planets contain water, which is the first time these planets have been confidently identified by scientists.
“We used to think that planets that were a little bigger than Earth were big balls of salt and rock, like extended versions of our own Earth, which is why we called them Super-Earths.” However, it is now clear to us that these two planets, Kepler-138c and Kepler-138d, are very different in nature: it is possible that a large part of their volume is made up of water.
“It’s the first time we’ve seen planets that we can confidently identify as watery, the kind of planets astronomers have long thought existed,” he explained.
Scientists haven’t found water directly, because it’s still hard from such a long distance. But research has shown that up to half of the planet must be made of something lighter than rock and heavier than hydrogen – which is what makes this stuff watery.
The two planets orbit the star Kepler-138, which is 218 years away and is located in the constellation Lyra.
Both planets have three times the mass of Earth, and twice the mass of Earth – but they are much smaller than Earth’s.
Planets orbiting Kepler-138 were first discovered in 2014, when they were observed using the Kepler telescope, and they were discovered using the transit method, in which scientists noticed the slight dip that occurs when planets pass in front of their star.
The new research builds on some of NASA’s Hubble and Spitzer space probes, which allow scientists to determine how planets formed. This additional data led scientists to believe that the two planets were of water origin.
Scientists have explained that the water worlds are nothing like the primordial planet we might imagine, with an area similar to that of Earth’s oceans in the beginning. In fact, these planets are so hot that water instantly evaporates, creating a dense atmosphere that can hide liquid water.
The two planets are also outside the habitable zone, and since they are too hot for liquid water, they may not be habitable. But a new study has discovered another planet in the system, called Kepler-138e, located in the habitable zone.
The planet is small in size, far from its star, and its year takes 38 Earth days, but scientists are still ignorant of its details, because it does not seem to pass in front of its star.