Two planets with size comparable to that of Earth have been confirmed to have rocky surfaces.
The discovery makes it more certain that the planets may be habitable. What strengthens the claim about the habitability of the planets is that their respective atmospheres are not as thick as Venus’ but not as thin as Mars’. The planets, called K2-72c and K2-72e, are in the “habitable zone” of the dwarf star they revolve around.
As reported by CNN, the habitable zone of a star is where liquid water could exist on the surface of the planet. The dwarf star the planets circle around is dimmer, cooler and has a significantly lesser size than that of the Sun. Since the planets are in the habitable zone, they are closer to their star.
Of the two, K2-72c is closer to its star. Its one year is 15 days on Earth, and it is as much as 10 percent warmer. Meanwhile, one year of K2-72e is equivalent to 24 days on Earth. It is 6% colder than our planet.
According to Space.com, the dwarf star such as the one in question constitutes almost 15 percent of all stars in the Milky Way.
The discovery of the surfaces of K2-72c and K2-72e was made on May 4 during a phenomenon known as double transit, which occurs when two planets pass in front of their star at the same time.
“We actually have the capabilities to study the atmosphere of potentially habitable worlds with a facility, Hubble, designed in the ’70s, well before we started to detect exoplanets,” lead author Julien de Wit, a planetary scientist at the Massachusetts Institute of Technology, said. “This is just insanely exciting.”