08-20-2019, 06:12 PM
Attempting to understand Io's volcanism
Io, one of Jupiter's major moons, has been known since Voyager 1's flyby in 1979 as volcanically active. The activity stems from tidal heating forces due to Jupiter and its other major moons, Europa and Ganymede, which keeps the interior of Io molten. More recent studies by Gemini and the Keck Observatories on Mauna Kea have shown volcanic activity on Io appears to cycle over a period of around 500 earth-days.
Io orbits Jupiter very quickly, in about 1.8 days, but it also has a longer period of around 480 days during which time its orbit changes. It's believed this long period cycle is responsible for the changes in Io's overall volcanic activity.
"By studying changes in Io’s surface brightness due to its volcanic activity, researchers discovered a pattern in the volcanism that appears to coincide with the 480-day variation in the moon’s orbital shape. This was unexpected because there is no detectable pattern associated with the 1.8-day period of a single orbit, even though this is the amount of time over which the most dramatic variations in the pull of gravity occur. To understand this puzzling result, the researchers note that the magma is likely too viscous to react to the changing gravity on the timescale of one orbit, but it can adjust its flow rate with the slower variation in the shape of Io’s orbit. This explains the long-term variations in the degree of volcanic activity."
https://www.gemini.edu/node/21215
More details can be found at
https://blogs.agu.org/geospace/2019/08/0...nic-tides/
Io, one of Jupiter's major moons, has been known since Voyager 1's flyby in 1979 as volcanically active. The activity stems from tidal heating forces due to Jupiter and its other major moons, Europa and Ganymede, which keeps the interior of Io molten. More recent studies by Gemini and the Keck Observatories on Mauna Kea have shown volcanic activity on Io appears to cycle over a period of around 500 earth-days.
Io orbits Jupiter very quickly, in about 1.8 days, but it also has a longer period of around 480 days during which time its orbit changes. It's believed this long period cycle is responsible for the changes in Io's overall volcanic activity.
"By studying changes in Io’s surface brightness due to its volcanic activity, researchers discovered a pattern in the volcanism that appears to coincide with the 480-day variation in the moon’s orbital shape. This was unexpected because there is no detectable pattern associated with the 1.8-day period of a single orbit, even though this is the amount of time over which the most dramatic variations in the pull of gravity occur. To understand this puzzling result, the researchers note that the magma is likely too viscous to react to the changing gravity on the timescale of one orbit, but it can adjust its flow rate with the slower variation in the shape of Io’s orbit. This explains the long-term variations in the degree of volcanic activity."
https://www.gemini.edu/node/21215
More details can be found at
https://blogs.agu.org/geospace/2019/08/0...nic-tides/