- By Jonathan Amos
- BBC Science Correspondent
Astronomers have detected a large plume of water vapor escaping into space from Saturn’s icy moon Enceladus.
The 504 km wide (313 miles) moon is best known for its geysers, but this one is much bigger.
The stream is about 9,600 km – about the same distance as flying from the UK to Japan.
Scientists are fascinated by Enceladus because its subsurface may contain a salty ocean — a source of water — that could hold the basic conditions to support life.
NASA’s Cassini mission (2004-2017) continued to fly by the geysers, sampling the water with its instruments and collecting evidence of the necessary chemistry — though not directly detecting the biology.
The new super plume was spied by the James Webb Space Telescope. Previous observations have tracked steam emissions for hundreds of kilometers, but this geyser is on a different scale.
The European Space Agency (Esa) calculated the outflow rate to be around 300 liters per second. That would be enough to fill an Olympic-sized swimming pool in a few hours, Issa said.
Webb was able to map the properties of the plume using its highly sensitive Near-Infrared Spectrograph (NIRSpec). Tool.
The instrument showed how much of the ejected water vapor (about 30%) feeds water into one of Saturn’s famous rings, an obscure torus called its E-ring.
“The temperature on the surface of Enceladus is minus 200 degrees Celsius. It’s freezing,” commented Professor Catherine Heymans, Astronomer Royal of Scotland.
“But in the core of the moon, we think there’s enough heat to heat this water. That’s what causes these worms to come out.
“We know that deep in our own ocean on Earth, under these conditions, life can survive. That’s why we’re excited to see these big blues on Enceladus. They’ll help us understand a little bit more about what’s going on, and the possibility of life, but it’s life like you and me.” There’s not going to be — it’s going to be deep-sea bacteria.”
Scientists have proposed a NASA mission called the Enceladus orbiter that will try to solve the open question of life.
As the name suggests, the mission will orbit the Moon and sample geysers like Cassini did — but with improved technology — and then land on the surface to sample objects.
If ever approved, the Orbilander would not fly for decades due to other priorities.
Meanwhile, NASA and ISA have probes headed for Jupiter’s ice-covered moons. These bodies also contain deep oceans of water, and because they are actually quite large, they may be good candidates in the search for extraterrestrial life.
For example, it is not known how long the tiny Enceladus held water in the all-important liquid state to support life; The Moon may have been frozen solid for a significant portion of the Solar System’s history, reducing its evidence of life.
In contrast, Jupiter’s larger moons, such as Europa (3,121 km in diameter) and Ganymede (5,268 km in diameter), may have had enough thermal energy to keep water liquid for long periods of time.
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