The telescope provides clearer images of Jupiter’s largest moon

British scientists have published the most detailed images of the icy surfaces of Jupiter’s two largest moons, Europa and Ganymede.

The team of planetary scientists from the University of Leicester’s School of Physics and Astronomy, led by PhD student Oliver King, used the European Southern Observatory’s Very Large Telescope (VLT) in Chile to observe and map the surfaces of the moons.

The observatory’s latest images provide new insight into the processes affecting the chemical makeup of massive moons, as well as the geological features of the moons, such as the long fault lines that traverse Europa’s surface.

The images show the mixture of chemicals that form the icy surfaces of Jupiter’s largest moons, Europa and Ganymede, two future destinations for new missions in the giant planet system.

Interestingly, Ganymede and Europa are two of the four largest moons orbiting Jupiter, known as Galilean moons.

Europa and Ganymede belong to the group of 79 natural satellites orbiting Jupiter

Europa is similar in size to the Earth’s moon, while Ganymede is the largest moon in the entire solar system.

During the observations, sunlight reflected off the surfaces of Europa and Ganymede was recorded at different infrared wavelengths, producing reflectance spectra. The scientists then analyzed the results using a computer model that compares each observed spectrum with the spectra of different substances measured in the laboratory.

In addition, they mapped the distributions of different materials on the surface, King said. As a result, the experiment revealed that Europa’s crust consists mainly of frozen water ice, while other non-frozen materials have been recorded that pollute the surface.

Ganymede’s observations, published in JGR: Planets, show that the surface is composed of two main types of terrain.

Interestingly, the small areas have large amounts of water ice, and the old areas are made up of unknown dark gray matter.

Areas of ice, shown in blue in the images, include the polar ice cap and craters, and an impact event revealed fresh, clean ice from Ganymede’s crust.

The team mapped how Ganymede’s ice grains vary on the surface and the potential distributions of a variety of different salts, some of which may have come from within the moon itself.

“The powerful telescope enabled detailed mapping of Europa and Ganymede, observing elements less than 150 km in diameter, all at distances greater than 600 million km from Earth,” King said. Until now, mapping at this precise scale was only possible by sending a spacecraft to Jupiter to closely monitor the satellites.