Planets with vapor atmospheres, oceans with liquid water and inner rock cores surrounded by ice can be abundant in space, in orbit around distant stars.
This is the conclusion of a new study from Harvard University, recently presented at the Goldschmidt 2018 geochemistry conference in Boston, USA.
According to the researchers, of the approximately 4,000 known exoplanets, near the 35% are worlds rich in water.
- The ingenious method that made it possible to decipher the secrets of one of the exoplanets closest to the earth
This property opens the possibility that can hold on to life.
Li Zeng – the researcher who presented the study – and his colleagues came to this conclusion, after analyzing the data of the most important "hunter" of exoplanets: the Kepler Space Telescope.
After analyzing the size of radio of every planet and are mass, created a model with which they could establish the relationship between the two to decipher the evolution and its composition.
The 4,000 exoplanets that are detected, they say, can be divided into two categories: those with a radius of about 1.5 compared to the earth (with a mass that is usually 5 times larger) and those with a radius of 2, 5 compared to our planet (with a mass similar to that of 10 earths).
"The model shows that exoplanets with a radius of 1.5 in comparison with the earth tend to be rocky planets"Zeng explained.
On the other hand, "those with a radius of 2.5 in relation to the earth are likely aquatic worlds".
- How the 7 new exoplanets announced by NASA appear on the earth (and how do they differ from each other?)
This means that 35% of all known exoplanets that are larger than the earth must be rich in water.
"These aquatic worlds were probably formed in the same way as the giant planetary nuclei (Jupiter, Saturn, Uranus, and Neptune) found in our own solar system," Zeng said.
Similar but different
However, the fact that these exoplanets can contain water does not necessarily make them comparable to our planet.
"It is water, but no ordinary waterlike the one we found on earth, "says Zeng.
"The surface temperature is estimated to be in the range of between 200ºC and 500ºC".
"It is possible that the surface is packed in an atmosphere dominated by water vapor, with a layer of liquid water underneath," concludes the researcher.
- How moons are formed and why it is important to find those of exoplanets
In the opinion of Sara Seager, Professor of Planetary Sciences at MIT, deputy director of the TESS mission, who recently started to look for these celestial bodies, "is it incredible think that the enigmatic exoplanets can be aquatic worlds with large amounts of water. "
"We hope that observations of their atmosphere in the future will serve to support or refute this new finding," Seager said.
Now you can receive notifications from BBC News World. Download the new version of our app and activate it to not miss our best content.