Saturn's moon Enceladus is blasting a plume of water 6,000 miles high. Could life be lurking under its icy shell?

a plume of water shooting out of a small moon
An image from NASA’s James Webb Space Telescope’s NIRSpec (Near-Infrared Spectrograph) shows a water vapor plume jetting from the southern pole of Saturn’s moon Enceladus, extending out more than 20 times the size of the moon itself. The inset, an image from the Cassini orbiter, emphasizes how small Enceladus appears in the Webb image compared to the water plume. (Image credit: NASA, ESA, CSA, Geronimo Villanueva (NASA-GSFC))

The James Webb Space Telescope has found a 6,000 mile-long plume of water squirting into space from Saturn's tiny, ice-covered moon Enceladus, creating a massive watery cloud in the ringed planet's orbit.

Saturn's moon Enceladus is one of the likeliest places in the solar system that might harbor extraterrestrial life. The new James Webb Space Telescope (JWST) observation suggests that the grand telescope may play a role in helping scientists to decide whether and how best to look for it.

NASA-led Cassini mission detected water plumes on Enceladus in 2005 during a series of close flybys. But at that time, scientists gained only a limited understanding of how powerful these geysers actually are. Now, JWST has allowed scientists to take another look at these watery jets and examine their composition. "With the James Webb telescope, we can measure water from far away and see the whole view for the first time," Geronimo Villanueva of NASA's Goddard Space Flight Center and lead author of the study, told Space.com. 

Related: Enceladus: Everything you need to know about Saturn's bright, icy moon

The Webb measurements revealed that the water torrent gushes out of the barely 300-mile-wide (500 kilometers) Enceladus at a speed of 79 gallons (360 liters) per second, NASA said in a statement, fast enough to fill an Olympic-sized swimming pool with water in a couple of hours. 

Although scientists expected to detect water on Enceladus, the result of Webb's first observation of the moon came completely by surprise.

"When we planned this, we thought we were going to see a little bit of water very close to the surface," Villanueva said. "We have never expected this type of emission of water."

The measurements revealed that despite its minuscule size,  Enceladus has a huge effect on the environment around the gas giant, which it orbits in less than two days. The geyser of water creates a huge watery cloud in the moon's wake that sits in Saturn's orbit and spreads towards the planet's other moons. Data analysis revealed that only 30% of the water that forms the donut-shaped water cloud remains in place. The rest, about 70%, spreads over the rest of the Saturnian system and beyond, according to NASA.

The emission spectrum of the water plume shooting out from Enceladus as measured by JWST. (Image credit: NASA, ESA, CSA, STScI, Leah Hustak (STScI))

Scientists are now curious what else might be spreading throughout the solar system with this powerful spray. Analysis of Cassini data previously found molecules in the Enceladus plume that might be signatures of life, like methane, carbon, oxygen and phosphorus. Scientists believe the little moon has all the necessary prerequisites for simple forms of life to emerge, as its liquid ocean is sandwiched between a thick shell of ice and a rocky core that provides a source of nutrients. 

The moon's close proximity to Saturn also means the core is subject to enormous gravitational forces that likely generate heat inside the moon and with it, possibly, the chemical reactions that might help microorganisms to emerge. 

Villanueva, however, said that Webb didn't find traces of these molecules during its first look at the intriguing water world. 

"We didn't see them in these measurements, but we are hoping that if things are there, we will be able to detect them in the future," Villanueva said. 

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Tereza Pultarova
Senior Writer

Tereza is a London-based science and technology journalist, aspiring fiction writer and amateur gymnast. Originally from Prague, the Czech Republic, she spent the first seven years of her career working as a reporter, script-writer and presenter for various TV programmes of the Czech Public Service Television. She later took a career break to pursue further education and added a Master's in Science from the International Space University, France, to her Bachelor's in Journalism and Master's in Cultural Anthropology from Prague's Charles University. She worked as a reporter at the Engineering and Technology magazine, freelanced for a range of publications including Live Science, Space.com, Professional Engineering, Via Satellite and Space News and served as a maternity cover science editor at the European Space Agency.

  • rod
    "The Webb measurements revealed that the water torrent gushes out of the barely 300-mile-wide (500 kilometers) Enceladus at a speed of 79 gallons (360 liters) per second, NASA said in a statement, fast enough to fill an Olympic-sized swimming pool with water in a couple of hours. Although scientists expected to detect water on Enceladus, the result of Webb's first observation of the moon came completely by surprise. "When we planned this, we thought we were going to see a little bit of water very close to the surface," Villanueva said. "We have never expected this type of emission of water."

    My thought. Just how long has this process been operating at Enceladus? Another note from the article.

    "Scientists are now curious what else might be spreading throughout the solar system with this powerful spray. Analysis of Cassini data previously found molecules in the Enceladus plume that might be signatures of life, like methane, carbon, oxygen and phosphorus. Scientists believe the little moon has all the necessary prerequisites for simple forms of life to emerge, as its liquid ocean is sandwiched between a thick shell of ice and a rocky core that provides a source of nutrients. The moon's close proximity to Saturn also means the core is subject to enormous gravitational forces that likely generate heat inside the moon and with it, possibly, the chemical reactions that might help microorganisms to emerge. Villanueva, however, said that Webb didn't find traces of these molecules during its first look at the intriguing water world. "We didn't see them in these measurements, but we are hoping that if things are there, we will be able to detect them in the future," Villanueva said."

    Okay, apparently the gravitational forces can create heat for the moon, and *chemical reactions that might help microorganisms to emerge*.

    Space.com has a variety of reports on abiogenesis and the creation of life from non-living matter. Here is a recent example.

    Meteorites and volcanoes may have helped jump-start life on Earth, https://forums.space.com/threads/meteorites-and-volcanoes-may-have-helped-jump-start-life-on-earth.61544/
    Reply
  • rod
    If I did my calculations correctly, 79 gallons per second = 1.12 x 10^19 gallons over 4.5 Gyr period. That is plenty of water and mass spewed out. Estimating in grams, about 3.6 x 10^22 g.
    Reply
  • rod
    On another note here, does this report about possible life at Enceladus, indicate the habitable zone for our Sun is now extended out to about 10 au? I looked at the exoplanet.eu site and found 677 exoplanets for class G stars. Pushing the HZ out to 10 au from those stars, looks like even more habitable exoplanets out there now :)
    Reply
  • Unclear Engineer
    Rod, If I did my math right, then your volume of 3.6x10^22 grams of water would equal a sphere 190 kilometers in diameter (assuming a density of 1 gram/cc).

    I guess that could be possible for a moon that is now 500 km in diameter.

    But, it seems like either Enceladus must have been a lot bigger 4.5 billion years ago, or this process must have started much later, or not have always been occurring at the current rate.

    Regarding the size of the "habitable zone" around a star, it doesn't seem like this phenomenon is pertinent to that. Even if Saturn was not orbiting the Sun, so long as it is rotating and Enceladus is orbiting it, maybe along with the other moons, the tidal heating would be occurring, even if outside our entire galaxy. So, I think we are really discussing habitable zones around giant planets as separate from habitable zones around stars, because the phenomena that create the temperature and pressures needed are different for the two types of zones.
    Reply
  • rod
    Unclear Engineer said:
    Rod, If I did my math right, then your volume of 3.6x10^22 grams of water would equal a sphere 190 kilometers in diameter (assuming a density of 1 gram/cc).

    I guess that could be possible for a moon that is now 500 km in diameter.

    But, it seems like either Enceladus must have been a lot bigger 4.5 billion years ago, or this process must have started much later, or not have always been occurring at the current rate.

    Regarding the size of the "habitable zone" around a star, it doesn't seem like this phenomenon is pertinent to that. Even if Saturn was not orbiting the Sun, so long as it is rotating and Enceladus is orbiting it, maybe along with the other moons, the tidal heating would be occurring, even if outside our entire galaxy. So, I think we are really discussing habitable zones around giant planets as separate from habitable zones around stars, because the phenomena that create the temperature and pressures needed are different for the two types of zones.
    Unclear Engineer, you calculations look good :) That indicates 190/500 is about 38% difference. I was getting values in that range for some 33-34% or so for total mass loss of water. Yes, looking at other G class stars and an HZ out to 10 au or so, gets interesting :)
    Reply
  • rod
    Unclear Engineer in post #5 said, "Regarding the size of the "habitable zone" around a star, it doesn't seem like this phenomenon is pertinent to that. Even if Saturn was not orbiting the Sun, so long as it is rotating and Enceladus is orbiting it, maybe along with the other moons, the tidal heating would be occurring, even if outside our entire galaxy. So, I think we are really discussing habitable zones around giant planets as separate from habitable zones around stars, because the phenomena that create the temperature and pressures needed are different for the two types of zones."

    The only confirmed exomoon presently that I see is Exomoon Kepler-1708 b-i, listed at http://exoplanet.eu/catalog/exomoon_kepler-1708_b-i/
    Reply