NASA spacecraft is about to approach the largest moon in the solar system

The Juno spacecraft is expected to pass close to Jupiter's moon Ganymede at 68,400 km/h over the next few days to collect data.

Color composite map (left) and geology (right) of the moon Ganymede, made with images from the Voyager and Galileo spacecraft. Photo: USGS/Wheaton/NASA/JPL-Caltech Planetary Geoscience Center.

The Juno spacecraft (NASA) will pass by Jupiter's moon Ganymede, the largest moon in the solar system, on June 7. With a diameter of more than 5,260 km, Ganymede is even larger than Mercury.

Juno has been observing Jupiter and its moons since July 2016. During its upcoming approach to Ganymede, the spacecraft will arrive 1,038 km above the celestial surface. This is the first spacecraft to approach Ganymede in more than 20 years. The most recent approach was made by the Galileo spacecraft in May 2000.

The camera on board Juno will take pictures of Ganymede while other instruments can collect data to help scientists understand more about the moon's composition, including its ice crust. "Juno is equipped with many sensitive instruments, able to observe Ganymede in unprecedented ways," said Scott Bolton, an expert at the Southwest Research Institute in San Antonio.

Ganymede is named after a wine servant to the ancient Greek gods. Not only is it the largest natural satellite in the solar system, it is also the only moon with a magnetic field. This causes the aurora to appear around the north and south poles.

Ganymede has an iron core and is covered by a layer of rock, topped by a thick crust of ice. Under the surface of this moon may exist an ocean. Astronomers also detected traces of a dilute oxygen atmosphere in 1996 using the Hubble Space Telescope, but this atmosphere is too thin for life to exist. On Ganymede's surface there are scattered bright areas. They look like scars and show that this celestial body was once heavily modified.

On June 7, Juno will use 3 cameras, including a navigation camera, to observe as much as possible, including the high-energy radiation around Ganymede. The approach will be very fast so there won't be time to take many photos. However, what was collected during this flight can be compared with the data that Voyager and Galileo have sent back.

"On Monday, Juno will fly by Ganymede at about 68,400 km/h. Less than 24 hours later, the spacecraft will continue to make its 33rd approach to Jupiter, passing through the planet's cloud tops at a high speed. It's going to be a spectacular flight," said Matt Johnson, Juno mission manager at NASA's Jet Propulsion Laboratory (JPL).