According to planetary scientist Tom Nordheim of the Johns Hopkins Applied Physics Laboratory and his team, the possibility of an ocean inside a small object like Miranda is quite surprising. According to the team, this shows that there may be environments that can host life even in the remote corners of our planetary system.
The mystery that started with Voyager 2
Images taken by the Voyager 2 spacecraft in 1986 revealed highly unusual geological structures in Miranda’s southern hemisphere. Miranda, whose surface is full of pits, ridges and cracks surrounded by steep slopes, is almost like a “Frankenstein” work with its complex structure. Many researchers suspect that these strange structures are a result of tidal forces and heating within the moon.
Considering that Miranda’s radius is only 235 kilometers, ocean would fill almost half of the moon. According to the researchers, the main source of heat inside Miranda is gravitational interactions with other moons of Uranus. Such interactions shape the satellite’s structure like a rubber ball, increasing the internal temperature. Like the resonance between Jupiter’s moons Io and Europa, Miranda and its neighboring moons once had a similar resonance. This resonance caused regular tidal forces to occur between the satellites, thus generating heat.
Over time, this resonance broke down and Miranda’s internal structure began to cool. However, researchers think that Miranda’s internal structure has not yet completely frozen. The researchers noted that if the inland ocean were completely frozen, there would be more cracks on the surface. This suggests that Miranda is still cooling and may even now have an ocean beneath its surface.
Parallel with Enceladus
For example, before the Cassini spacecraft reached Enceladus in 2004, many scientists thought the moon was a frozen ball of ice and rock. However, Saturn’s moon Enceladus proved to be a geologically active moon, reversing scientists’ predictions. Water vapor and ice particles spewing from the surface of Enceladus have become a promising target for the search for life beyond our planet. In fact, Enceladus is currently the primary target in the search for life beyond Earth.