Link Between Moonquakes and Landslides: Could Tectonic Activities Possibly Shape Terrains of Jupiter and Saturn’s Icy Moons?

A new study from NASA explains the link between seismic activities and terrain formation on the surfaces of the icy moons of Jupiter and Saturn. As more space probes are sent to the far ends of our Solar System, more significant information is gathered about the icy moons.

(Photo: Pexels/ T Keawkanok)

A Closer Look at the Icy Moons

Since Galileo Galilei discovered the four moons of Jupiter in the 17^th century, a lot has been known about them and other moons surrounding the gas giants. Known as icy moons, these natural satellites have become a subject of interest to many astronomers. In the past decades, several space probes were sent by NASA to learn more about their characteristics.

During the expedition of Voyager 1 in March 1979, it was observed that Europa contains smooth surfaces with dark and light terrain areas. Icy ridges were also noted, which represent depressed and elevated areas. The same space probe also observed the fractured terrain on another Jovian moon, Ganymede.

On the other hand, further exploration of the moons of Saturn reveals the presence of roughly parallel faults near the south pole of Enceladus. There are also curved grooves that separate the highly cratered areas.

Unfolding the Mystery of the Ridges

Jupiter's Europa and Ganymede and Saturn's Enceladus are known for having landscapes containing steep ridges with surrounding smooth areas, as confirmed by NASA's Galileo Spacecraft. According to NASA, it was earlier concluded by scientists that these could be the result of liquid flow from icy volcanoes. However, this process is impossible when the moon's surfaces have cold temperatures and are inhospitable to fluids. It turns out that a simple explanation does not involve liquids.

A study was conducted by a group of researchers led by University of Arizona in Tucson graduate student Mackenzie Mills to understand this phenomenon further. Using images gathered by NASA's Jet Propulsion Laboratory in Southern California, they measured the dimensions of the steep ridges along the surfaces of the icy moons. These elevated landforms were formerly believed to be tectonic fault scarps formed when one side of the surface drops after breaking along a fault line. Here on Earth, similar formations result when the crust breaks due to tectonic faulting.

The result of the study, published in Space.com, found that geological activities could have triggered landslides that helped smooth out the surface ridges. It shows the connection between moonquakes and landslides, showing how the surfaces and textures of the icy moons develop.

The moons of Jupiter and Saturn are known for being active due to the gas giants' gravitational effect, causing these natural satellites to get squeezed. As Jupiter and Saturn exert strong gravitational forces towards the bodies circling them, the moonquakes cause the crusts and surfaces of the moons to crack. In short, seismic events could be strong enough to make surface materials roll downhill in landslides.

Further information will be provided as NASA's Europa Clipper mission explores Europa in 2024. As more imagery and significant data are collected, scientists will try to determine if it contains a deep internal ocean under an outer ice shell with the possibility of hosting life.