Space Science: Cassini Dives Through Water Jets On Saturn’s Moon

This week, NASA’s Saturn-orbiting spacecraft Cassini flew through plumes of water on Saturn’s moon Enceladus. This historic maneuver may help establish the moon’s ability to support life.

Scientists recently discovered that a salty ocean lies beneath the ice-covered Enceladus. Similarly, one of Jupiter’s moons, Europa, is also believed to have a sub-ice ocean, making these bodies of intense interest for future missions looking for habitable spots in the solar system.

“This is a very big step in a new era of exploring ocean worlds in our solar system,” Curt Niebur, Cassini program scientist at NASA, said at an Oct. 26 conference announcing the flyby.

Cassini has flown by Enceladus water plumes, which spray through fractures in the moon’s icy surface, many times before. However, this event took the craft only 30 km above the surface and directly through the plumes, where spectrometers monitored the chemical makeup of the liquid.

During previous flybys, scientists had identified NaCl, CO₂, and organic molecules such as methane and formaldehyde in the plumes. With this close flyby, the scientists are looking for confirmation of the presence of H₂, which is produced through geothermal chemistry and will help establish Enceladus’s level of hydrothermal activity.

The team will spend the coming weeks analyzing the data before announcing their findings.