Two of Uranus' moons may support active oceans, study finds

Similar measurements have previously led to the identification of the ocean moons of Europa (Jupiter) and Enceladus (Saturn). The team also suggests that a few other largest moons of Uranus could also have subsurface oceans.

The results have been accepted for publication in the journal Geophysical Research Letters and were presented at the annual Lunar and Planetary Science Conference on March 16.

The possibility of a liquid ocean 

This strange activity was discovered when scientists re-examined nearly 40-year-old radiation data collected by NASA's Voyager 2 — the only spacecraft to visit Uranus.

The spacecraft's Low-Energy Charged Particle (LECP) instrument collected the particle data, as it passed by Uranus about four decades ago.

They discovered unusual plasma activity between the moons, Ariel and Miranda. “What was interesting was that these particles were so extremely confined near Uranus’ magnetic equator,” Cohen said in a statement.

The observations from Voyager 2 were recreated using physical models. The team has drawn two conclusions from this: the particles form either through a vapor plume (similar to Enceladus) or through sputtering.

After years, Uranus has risen to the forefront of scientific research. And space agencies, such as NASA, are once again preparing to investigate this distant world. However, the mission is not scheduled to begin until the end of this decade. Until then, scientists must study the planet using data from Voyager 2.

Study Abstract:

In situ exploration of Uranus has been limited to a single flyby encounter by the Voyager 2 spacecraft in January 1986. Nonetheless, new investigation has led to significant questions about the origin of energetic ions observed in the region between its moons Miranda and Ariel. Radial and pitch angle diffusion modeling suggests that typical magnetospheric sources cannot explain the observed characteristics of these energetic ions. We suggest that these are likely being introduced by a source from one of these moons and give rise to waves that could result in the observed particle distribution characteristics. This may reveal that internal plasma sources in the system may be important for Uranus’ magnetospheric dynamics and may contribute to its unexpectedly strong radiation belts.