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Ganymede, Jupiter’s largest moon, shows signs of past tectonic activity

Published: 07th December, 2018 at 04:00
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Galileo spacecraft data suggests fault lines that shear against one another horizontally, like the San Andreas fault found in California.

Ganymede, Jupiter’s largest moon, appears to have previously been through periods of intense tectonic activity, a team at the University of Hawaii has found.


Ganymede is believed to consist of vast subterranean oceans covered by an icy shell. A study using imagery collected by the Galileo spacecraft that orbited Jupiter between 1995 and 2003 has found evidence of violent ‘strike-slip’ tectonics. This causes fault lines that shear against one another horizontally, like the San Andreas fault found in California.

“The unexpected finding was how commonplace strike-slip faulting was. Indicators of strike-slip were observed at all nine sites, representing various geographic locations on Ganymede,” said Dr Marissa Cameron, who took part in the research.

Though Ganymede is no longer tectonically active, another of Jupiter’s moons, Europa, is. Europa is also thought to harbour a subterranean ocean, and is believed to be a likely candidate for finding extraterrestrial microbial life in the Solar System. “Incorporating our observations with previous studies provides an improved representation of Ganymede’s tectonic history and allows us to learn more about its neighbour, Europa,” said Cameron.

A new orbiter, Europa Clipper, is being developed by NASA and is scheduled to launch sometime between 2022 and 2025. It is planned to make 45 orbits of Europa to further investigate its habitability.

The Solar System’s top 20 moons ranked. Why? Because we can… © NASA


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Jason Goodyer
Jason GoodyerCommissioning editor, BBC Science Focus

Jason is the commissioning editor for BBC Science Focus. He holds an MSc in physics and was named Section Editor of the Year by the British Society of Magazine Editors in 2019. He has been reporting on science and technology for more than a decade. During this time, he's walked the tunnels of the Large Hadron Collider, watched Stephen Hawking deliver his Reith Lecture on Black Holes and reported on everything from simulation universes to dancing cockatoos. He looks after the magazine’s and website’s news sections and makes regular appearances on the Instant Genius Podcast.


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