Science and Exploration

Webb Telescope Captures Giant Water Plume Coming From Saturn’s Moon Enceladus

By Natalia Mesa
June 7, 2023
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Webb Telescope Captures Giant Water Plume Coming From Saturn’s Moon Enceladus
Saturn’s moon Enceladus.
Image credit: NASA/JPL/Space Science Institute.

In images captured from the James Webb Space Telescope, NASA scientists have spotted a massive geyser rocketing immense plumes of water vapor from the southern pole of Saturn‘s moon Enceladus, one of the only potentially-habitable celestial bodies in the solar system. Volcanic activity on Enceladus is launching water vapor 6,000 miles (10,000 km) from its surface, leaving a watery trail as the icy moon makes its way around Saturn. The new images may help researchers plan future missions to the frozen moon in search of habitable conditions or even signs of life.

Enceladus has captured planetary scientists’ attention because it is one of the only bodies in our solar system that could have the potential to sustain life. Below the moon’s icy crust lurks a sub-surface ocean (which is the source of the plume) that contains nitrogen and carbon compounds that are necessary for life.

Enceladus is 79 million miles from Earth, and this is the first time astronomers have captured any celestial body spewing giant plumes of water from such a distance. The Cassini Saturn orbiter took a snapshot of the moon’s dramatic waterworks when it flew by in 2005. The findings also show that Enceladus provides the rest of the moons orbiting Saturn with water, which may be affecting the composition of the entire system of Saturn and its rings.

Christopher Glein, an astronomer at the Southwest Research Institute who was involved in the Cassini mission but not in the current work, told SpaceRef that “it was shocking to actually know that the James Webb telescope can see that plume.” The findings now show that what Cassini captured wasn’t just a one-time occurrence, he adds; Enceladus is consistently shooting giant plumes of water into space.

Geronimo Villanueva, a planetary scientist at NASA Goddard Space Flight Center who led the study, told SpaceRef that when he and his team started the project, they didn’t expect to make any big discoveries. “That changed when we got this data,” he said.

The observations were captured within just four minutes of data. “It was pretty shocking,” Villanueva said. “When you point the Webb telescope and you see the moon, it’s a single pixel. Then you see the plume, which is covering your entire field of view. And it’s just water everywhere.”

“The Webb telescope such powerful instrumentation,” Sarah Faggi, an astronomer at NASA Goddard Space Flight Center who was involved in the work, told SpaceRef. “It’s incredible.”

The images were captured from Webb’s Near-Infrared Spectrograph (NIRSpec), which measures the emission spectra of incoming light to identify the molecular composition of faraway objects. The images showed that as Enceladus makes its 33-hour journey around Saturn, it creates a torus of water vapor collocated with Saturn’s outermost ring. The researchers estimated that about 30 percent of the water stays in the torus, while the rest goes elsewhere in the Saturn system, including to other moons.

“Enceladus is basically spilling out its guts and spewing water all over the place, so it’s going to affect the surface properties and chemistry on lots of moons of Saturn,” Glein said.

The scientists say that the new images will help them gear up for future missions and experiments to explore Enceladus, which will be conducted both on Earth and in space. So far, the researchers haven’t been able to detect any organic compounds in the plume, like carbon compounds and nitrogen compounds, which were detected in the Cassini mission. So, in the near term, astronomers plan to capture even more data with the James Webb Space Telescope in different parts of the orbit to look for these compounds.

“The search for life is a long process,” Villanueva said. But he adds that with these observations, “we can start planning ahead from here. Over the next 10 years, as we build things that go and fly to Enceladus, we can provide better guidance on where to go, where to land, where to make [more] observations.”

Natalia Mesa

Natalia Mesa is a neuroscientist turned journalist based out of Seattle, Washington. She writes stories on all aspects of science and health. Her work has appeared in The Atlantic, The Scientist, Science, Scientific American, and others.