The circle is closing more and more around possible exoplanets that could host life thanks to the presence of water. So much so that a team of astronomers from the University of Puerto Rico has drawn up a list of the 9 candidates. They are as follows:
– Gliese 581g : It is a super-earth discovered in 2010 that is located about 20 light years away in the constellation of Libra. The orbit to its star is about 36 Earth days and its temperature ranges between 37 and -12 degrees Celsius.
– Gliese 667Cc : A super-earth, in this case discovered in 2012, located in a triple star system in the constellation Scorpio. Like the previous one, it is also found in the Gliese 581 planetary system. This exoplanet orbits its star in a period of 28.1 days, making it the most Earth-like planet. However, it has a remarkable drawback: its star is a red dwarf and therefore stellar eruptions would surround the planet with ultraviolet radiation or X-rays.
– Kepler 22b : It is 2.4 times larger than Earth, but its location with respect to its star makes it another viable candidate to contain life. Experts believe that the surface temperature could be around 22 degrees Celsius.
– HD 40307g : Located 42 light years away, this extrasolar planet has a mass up to 7 times that of Earth. Fortunately, its orbit with respect to its star is very similar to that of Earth with respect to the Sun.
– HD 85512b : This planet is 3.5 times the size of Earth and is also at an ideal distance from its sun to host liquid water on its surface if its atmosphere allows it.
– Tau Ceti e : Of all the candidates this is the closest to us. Its average temperature could be 49 degrees Celsius and its gravity could be twice that of Earth. These conditions limit the presence of life to organisms with the ability to withstand extreme temperatures.
– Gliese 163c: This planet, which is located at a distance of 50 light years, orbits its star every 26 days. Despite these conditions, its mass, which is 7 times the mass of the Earth, makes it a gigantic rock or a huge ball of gases.
– Gliese 581d : Its mass is also 7 times greater than that of the Earth and, studies on its composition suggest that it could have a thin atmosphere of carbon dioxide.
– Tau Ceti f: This super-Earth is 6 times more massive than Earth. In this case, if its atmosphere were favorable, it could host the ideal conditions for life.
