The Ganymede troughs, which dominate the surface of the largest moon in the solar system’s solar system, may have been created by a collision between a large object up to 90 miles (150 km) wide.
This is according to a paper that Japanese scientists published on preprint service arxiv.org. It is the largest known impact structure in the solar system if the theory is true.
Ganymede, one of Jupiter’s 79 moons, is larger than Pluto or Mercury. It measures 3,273 miles/5 268 kilometers in diameter. It is the only known moon to have a magnetic field. It is also believed to have an underground saltwater ocean.
Ganymede has a pock-marked surface that is grooved, patterned and grooved. According to the paper, the furrows that run across Ganymede’s surface are part a concentric system tectonic-troughs. The paper states that “if this multi-ring structure was of impact origin, it is the largest impact structure so far in our solar system.” Although it is difficult to estimate the size of an impactor, a 150km radius impactor is consistent in the observations of furrows.
Images taken by NASA’s Voyager 1 & 2 probes in 1979 were used by the scientists, as well as images taken by NASA Galileo spacecraft which orbited Jupiter between 2001 – 2003.
NASA’s Juno spacecraft captured Ganymede during close flyby in June 2021.
Future explorations of Jupiter’s moons could confirm the theory, most notably by JUICE (Jupiter Icy Moon Explorer) mission by European Space Agency.
JUICE will launch on April 5-25, 2023 aboard an Ariane 5 rocket, from Europe’s Spaceport, France Guiana, South America. It will be launched in 2031, and will spend three-and-a-half years studying two of Jupiter’s moons Europa (or Callisto) before entering orbit of Ganymede on September 20, 2032. It will be the first spacecraft to orbit another moon than Earth’s Moon.