Saturn’s icy moon Enceladus harbours a vast ocean of liquid water beneath an icy crust that may be capable of supporting life, NASA scientists say. Gravity measurements suggest a large, possibly regional, ocean about 10 kilometres deep, beneath an ice shell about 30 to 40 kilometres thick.
NASA’s Cassini spacecraft and Deep Space Network uncovered that Enceladus is home to a large underground ocean of liquid water, furthering scientific interest in the moon as a potential home to extraterrestrial microbes.
Researchers theorised the presence of an interior reservoir of water in 2005 when Cassini discovered water vapour and ice spewing from vents near the moon’s south pole. The new data provide the first geophysical measurements of the internal structure of Enceladus, consistent with the existence of a hidden ocean inside the moon.
“As the spacecraft flies by Enceladus, its velocity is perturbed by an amount that depends on variations in the gravity field that we’re trying to measure,” said Sami Asmar of NASA’s Jet Propulsion laboratory in Pasadena, California, a coauthor of the paper. “We see the change in velocity as a change in radio frequency, received at our ground stations here all the way across the solar system,” said Asmar.