A detailed analysis of Cassini probe data confirms regular fresh ice formation across Enceladus' northern hemisphere. Findings are published in the journal Icarus.
In 2017, after 13 years orbiting Saturn and over 20 years in space, NASA's Cassini spacecraft, low on fuel, executed a dramatic dive into the planet's atmosphere. Though the mission ended, its vast dataset continues to yield insights into the gas giant and its moons, analyzed by experts worldwide.
A NASA team recently leveraged data from Cassini's Visible and Infrared Mapping Spectrometer (VIMS) to deepen our understanding of Enceladus' geological activity.
By examining light reflected from Saturn, its rings, and nearby satellites onto Enceladus' surface, the VIMS instrument—capable of dissecting light into spectral wavelengths—enabled precise determination of surface composition.
For 15 years, we've known Enceladus ejects icy plumes from its south pole, resurfacing the area. This global spectral map's infrared signals affirm that activity.
Surprisingly, similar infrared signatures appear in the northern hemisphere—far less prominent than in the south, yet undeniably present—indicating ongoing resurfacing in both regions.
"Infrared observations confirm the south pole's young surface, consistent with known icy jets," says Gabriel Tobie, co-author from the University of Nantes, France. "Now, these spectral insights reveal much of the northern hemisphere appears equally young, suggesting recent activity."
In the north, this fresh ice likely originates from Enceladus' subsurface ocean, propelled to the surface via plumes like those in the south or through gradual crustal fractures.
Enceladus ranks among top targets for extraterrestrial life detection, alongside Europa and Mars. Recent studies indicate its subsurface ocean is ancient enough to harbor microbial life, with sufficient nutrients to sustain it.
