According to new research, exomoons (natural satellites of planets outside our Solar System) could offer another clue about the pool of alien worlds that may be home to life.
Only a small proportion of exoplanets are likely to be able to sustain life, existing in the habitable zone of their stars. But some planets, especially large gas giants, may harbor moons which contain liquid water.
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 habitable zones of systems that scientists are trying to find Earth-like planets in.
Researchers looked at the possibility of exomoons orbiting J1407b, a large gas giant believed to have an enormous ring system. J1407b circles a 16-million-year-old Sun-like star approximately 434 light-years away from Earth. The planet’s mass is thought to be in the range of about 10 to 40 Jupiter masses.
Scientists ran computer simulations to model the rings around J1407b, which are 200 times larger than those around Saturn. Gravitational forces between particles were calculated and used to update the positions, velocities, and accelerations in the computer models of J1407b and its ring system. They then added a moon that orbited at various ratios outside of the rings to test whether this caused gaps to form where they expected.
The 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 J1407b’s rings.
The paper was published in the Monthly Notices of the Royal Astronomical Society.