In a place once thought to be the darkest and most desolate in the Solar System, NASA's Voyager 2 spacecraft has made a shocking discovery.
A research team led by scientist Tom Nordheim from the Johns Hopkins Applied Physics Laboratory (APL – USA) revisited nearly 40-year-old data from one of NASA’s most distant spacecraft in history.
That spacecraft is Voyager 2, which exited the heliosphere a few years ago. However, back in 1986, it flew past a seemingly barren moon named Miranda.
Miranda is the smallest and innermost of Uranus' moons, named after a character in William Shakespeare’s play The Tempest.
It is one of the smallest spherical objects in the Solar System, shaped by its own gravity, with a radius of only 235 km and a highly complex surface.
Miranda has been known for a long time, but it was widely believed to be a barren rock, much like most celestial bodies in the dark and distant regions of space.
However, the research team has now mapped various surface features of Miranda and developed a computer model to simulate its internal structures. Their findings reveal something astonishing: a subsurface ocean.
This ocean is estimated to be up to 100 km deep, encased within a rocky and icy shell up to 30 km thick, and has likely existed for 100 to 500 million years.
Researchers estimate that the ocean makes up nearly half of Miranda’s total volume.
“Finding evidence of an ocean inside such a small object as Miranda is incredibly surprising,” Dr. Nordheim told Space.com.
The study also suggests that in the past, tidal interactions between Miranda and neighboring moons played a crucial role in keeping its interior warm enough to sustain a liquid ocean.
More specifically, gravitational stretching and compression of Miranda, amplified by orbital resonance with other moons, could have generated enough frictional energy to maintain internal warmth.
However, Miranda eventually lost its synchronization with one of Uranus’ other moons, deactivating this internal heating mechanism.
Still, researchers do not believe Miranda has completely frozen over. If it had, the process would have caused surface expansion and large cracks, which have not been observed.
According to Newsweek, where there is water, there is a chance for life. Thus, scientists consider Miranda a promising target for future missions searching for extraterrestrial life.
