Distant moons may harbour alien life: study

Massive moons of exoplanets are the right size, in the right position and have sufficient water to support life beyond Earth, a new study suggests.
Using data from the solar system and observations of huge planets far beyond the visual range of any telescope, researchers at the McMaster University in Canada have shown that some moons of those planets could be habitable.
"We could be just a few decades from proving if there is life elsewhere," Rene Heller, a post-doctoral fellow at McMaster's Origins Institute.
"For all this time, we have been looking on other planets, when the answer could be on a moon," said Heller.

Exoplanets are being counted in the thousands since the development of new, non-visual methods that allow scientists to prove their existence by measuring light patterns from sun-like stars that dim slightly as the planets pass in front of them in orbit.
Many planets outside the solar system are even more massive than Jupiter, and they orbit their Sun-like stars at an Earth-like distance, but these faraway super-Jupiters are effectively giant gas balls that cannot support life because they lack solid surfaces.

Their moons, though, might have the right conditions for liquid surface water and therefore for life to emerge and evolve, researchers said.

While recent research has focused on exoplanets, the researchers are eager to study the moons of those giant Jupiter-like planets, which they believe to have migrated into more temperate ranges of distant stars, towing watery moons in their orbits.
Heller and Ralph Pudritz, professor of physics and astronomy, modelled the early life of Jupiter, revealing a pattern of ice distribution on Jupiter's moons that led them to predict the formation of moons around the super-Jupiters of other solar systems. Those moons could be twice as massive as Mars.
No moon around an exoplanet, a so-called exomoon, has been discovered as of today, but they are certainly there, Heller said.

With about 4,000 exoplanets known to exist so far, and with increasing technological capabilities, an exomoon discovery is now looming on the horizon, researchers said.
The finding was published in the journals Astronomy and Astrophysics and The Astrophysical Journal.