NASA: Saturn Moon Water Plume Twice the Size of US

NASA, using the James Webb Space Telescope, detected a vapor plume more than twice the width of the U.S. streaming out of one of Saturn’s moons, according to a report Tuesday by Newsweek.

The plume, which measures at least 6,000 miles long, is the first water emission of this magnitude to be detected by NASA, and it offers a direct look at how the moon, Enceladus, supplies water to Saturn and its rings.

Coated in a distinctive, icy outer shell that gives it the whitest, most reflective surface in this solar system, Enceladus is one of more than 120 moons that circle Saturn. Its 313-mile diameter runs roughly as wide as Arizona.

“When I was looking at the data, at first, I was thinking I had to be wrong,” Geronimo Villanueva, lead author of the Enceladus study and a planetary scientist at NASA’s Goddard Space Flight Center in Maryland, said in a statement. “It was just so shocking to detect a water plume more than 20 times the size of [Enceladus]. The water plume extends far beyond its release region at the southern pole.”

According to NASA, Enceladus’ icy spray spreads into space around its orbit, forming a ring of its own, known as Saturn’s E ring. First observed in 1966, the E ring is less sharply defined and not nearly as flat as Saturn’s other rings. Its shape resembles that of a torus — a faint, wispy donut that encircles the planet.

“The orbit of Enceladus around Saturn is relatively quick, just 33 hours,” Villanueva explained. “As it whips around Saturn, the moon and its jets are basically spitting off water, leaving a halo, almost like a donut, in its wake.”

Using the Webb telescope, Villanueva and his team found that approximately 30% of the ejected water feeds into the E ring. The remaining 70% supplies water around Saturn, its rings, and other moons.

Enceladus’ enormous plumes are also extremely fast. Scientists determined that water vapor gushes out from the moon at a rate of about 79 gallons, or 300 liters, per second — fast enough to fill an Olympic-sized swimming pool in just a few hours. Newsweek compared that to filling a pool that size with a garden hose, which would take more than two weeks.

The plumes were first detected nearly 20 years ago during NASA’s Cassini mission, though the spacecraft’s limited software vastly underestimated the size of the propulsions. However, measuring their speed has produced fairly consistent results throughout the past two decades, indicating that the moon’s activity has also remained steady during that time.

Such activity further supports NASA’s characterization of the moon — which it has also described as an “ocean world” — as one of the most capable of hosting extraterrestrial life, especially due to the presence of nitrogen and oxygen-bearing compounds in its oceans.

Jonathan Lunine, a planetary scientist at Cornell University, agrees that Enceladus’ steady activity could be indicative of its suitability to host alien life. NASA’s latest findings “only enhances my excitement about going to Enceladus to search for biosignatures,” he told the journal Science on Tuesday.

Results from the Enceladus study come about a week after NASA’s Ames Research Center in California’s Silicon Valley, after examining data from the Cassini mission from 2004 to 2017, provided evidence that Saturn’s rings, in astronomical terms, are young and temporary. Scientists estimated that the age of Saturn’s rings fall between 100 million and 400 million years.

Villaneuva and his team’s Enceladus study of the Webb telescope’s observations has been accepted for publication by the journal Nature Astronomy, and is available at NASA’s website.