This enhanced image of the Jovian moon Ganymede was obtained by NASA’s JunoCam imager. … [+]
According to new research, Ganymede, the largest moon in the solar system, was hit by an asteroid 20 times larger than the one that ended the dinosaur era on Earth.
The collision, which took place about four billion years ago, was so massive that it shifted the giant moon’s axis – and the telltale signs are still there.
unique month
Ganymede Larger than Mercury and only slightly smaller than Mars, Ganymede is 3,273 miles/5,268 kilometers in diameter. It is the largest moon and the ninth largest body in the solar system after the eight planets. It is also the only planetary moon that has both an atmosphere and a magnetic field.
It is also the only one of the four large Galilean moons of Jupiter (the others being Europa, Callisto, and Io) whose surface is dominated by grooves that form concentric circles around a specific point.
In May 2022, it was claimed that Ganymede’s pockmarked, grooved, and patterned surface may have been created by a 90-mile-by-150-kilometer-wide asteroid. which is now under review.
Kobe University’s Hirata Naoyuki was the first to notice the impact site of an asteroid … [+]
Ganymede grooves
“Jupiter’s moons Io, Europa, Ganymede and Callisto all have interesting individual features, but what caught my attention were the grooves on Ganymede,” says Kobe University planetary scientist Hirot Naoyuki and author of the paper, published today in Scientific Reports. was . We know this feature was created by an asteroid impact about four billion years ago, but we weren’t sure how big the impact was and what effect it had on the moon.
Huge impact
Hirata, who specializes in simulations of impact events involving moons and asteroids, calculated that the asteroid that hit Ganymede by changing its spin axis would probably have been about 186 miles (300 kilometers) in diameter.
That’s about 20 times larger than the asteroid or comet that hit Earth 66 million years ago, creating the 110-mile (180-kilometer) Chicxulub crater near Mexico’s Yucatan Peninsula. This probably led to the decades-long winter impact that killed the dinosaurs.
Recent research has shown that the dinosaur-killing asteroid outside the orbit of Jupiter during the early development of our solar system.
Jupiter’s moon Ganymede is covered over large parts of its surface by grooves (right). … [+]
Oxygen and ice
Astronomers using the Hubble Space Telescope have found evidence of a thin atmosphere of oxygen on Ganymede, which they believe comes from its icy surface, according to NASA. Also using data from the Hubble Space Telescope, a 2021 study announced that scientists had found the first evidence for water vapor in the atmosphere of Jupiter’s giant ice moon, Ganymede. Ganymede is also thought to have a subterranean ocean beneath its icy surface.
Juno and juice
NASA’s Juno spacecraft visited Ganymede on a short flyby in 2021 and photographed its grooved and patterned surface — clues to what happened to the moon four billion years ago. Data collected by Juno show that mineral salts and organic compounds are present on the surface of Jupiter’s giant moon Ganymede.
The European Space Agency’s Jupiter ICy Moons Explorer (JUICE) spacecraft is currently on its way to Jupiter, where it will orbit Ganymede for six months starting in 2034. This will be the first ever mission to the moon of another planet.
Wishing for a clear sky and big eyes
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