Exomoons might have better chances of harboring alien life forms -- especially technological and intelligent life -- compared to rocky planets like the Earth.

This relatively new hypothesis about the existence of life on exomons was made anew in a study conducted by the University of Lincoln in the United Kingdom. Nearly 4,000 exoplanets have been discovered thus far and more are being discovered daily. Most of these planets are believed to have moons orbiting them.

The study published in the journal, Monthly Notices of the Royal Astronomical Society, noted only a small proportion of these exomoons are likely capapble of sustaining life, but their larger numbers compared to rocky planets mean the chances of life thriving in these moons is much greater.

Some exomoons, especially those orbiting large gas giants, might have surface or subsurface liquid water. These moons can also maintain their water despite their presence outside the habitable or zone.

"These moons can be internally heated by the gravitational pull of the planet they orbit, which can lead to them having liquid water well outside the normal narrow habitable zone for planets that we are currently trying to find Earth-like planets in," said Phil Sutton from the University of Lincoln.

"I believe that if we can find them, moons offer a more promising avenue to finding extra-terrestrial life.”

The study looked at the possibility of moons orbiting the exoplanet J1407b. It analyzed if these moons might have caused gaps in the planet's ring system. Researchers ran computer simulations to model the rings around J1407b, which are 200 times larger than those of Saturn’s.

Findings revealed that while the orbiting moon did have an effect on the scattering of particles along the ring edge, the expected gaps in the ring structure were unlikely to be caused by the gravitational forces of a currently unseen moon orbiting outside the rings.

The existence of Exomoons continues to be inferred as detecting them is extremely difficult because current methods are limited to transit timing. It’s possible some of the attributes of exomoons might be determined by similar methods as those of transiting planets.

NASA continues to launch missions that seek planets outside the Solar System, which could host alien life. Pixabay

Some scientists, however, estimate there are as many habitable exomoons as habitable exoplanets.

Large Saturn or Jupiter sized gas planets in the habitable zone are thought to be the best candidates to harbor Earth-like moons given the general planet-to-satellite mass ratio of 10,000.

In October 2018, scientists announced the discovery of a potential exomoon orbiting Kepler-1625b, an exoplanet orbiting the yellow star Kepler-1625 about 8,000 light-years away.