Discovered by Galileo Galilei in 1610, Ganymede (Jupiter III), one of the four Galilean moons of Jupiter, is the largest natural satellite of said planet and of the Solar System, in addition to being the only one with a magnetic field. In addition, NASA astronomers have detected water vapor in the atmosphere, which could be an indication of the presence of life.
The latest research supported by data from Hubble suggests that the satellite contains a large ocean of salty water underground, even larger than all the water on the Earth’s surface and it is believed that it could have several layers of ice and water interspersed between its crust and core.
The giant icy satellite
On June 7, 2021, NASA’s Juno spacecraft flew by Jupiter’s giant moon, whose diameter reaches 5,268 kilometers, making it larger than planets like Mercury and three-quarters the size of Mars. In turn, it is the only one that has a magnetic field, which would have originated from convection movements inside the molten iron core.
Ganymede was chosen for detailed investigation as it provides a natural laboratory for analysis of the nature, evolution, and potential habitability of icy worlds, the role it plays within the Galilean satellite system, and its magnetic and plasma interactions with Jupiter. and his or her environment.
The presence of salt water above the rocky core generates chemical reactions between the rocks and the water that could lead to the formation of life according to scientists.
Water vapor on Ganymede
On July 28, 2021, astronomers discovered evidence of water vapor in the atmosphere of Jupiter’s moon Ganymede. This water vapor is formed when the ice on the moon’s surface sublimates, that is, changes from a solid to a gas. Scientists used new archive and data sets from NASA’s Hubble Space Telescope to make the discovery, published in the journal Nature Astronomy.
Where there is water there can be life, although by itself it is not enough: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur would also be needed, the six elements constitute 98% of the living matter on Earth.
Ganymede contains more water than all the oceans on Earth. However, the temperatures are so cold that the water on the surface freezes. Ganymede’s ocean is located approximately 160 kilometers below the crust; therefore, water vapor does not compromise the evaporation of this ocean.
“So far only molecular oxygen has been observed,” explained Lorenz Roth of the KTH Royal Institute of Technology in Stockholm, Sweden. “This occurs when charged particles erode the ice surface. The water vapor we now measure originates from ice sublimation caused by thermal escape of water vapor from warm and icy regions.”
The European Space Agency (ESA) plans to launch the JUpiter ICy moons Explorer (JUICE) mission in 2022, arriving in 2029. It will spend at least three years making detailed observations of Jupiter and three of its largest moons, with a special focus on Ganymede. as potential habitat.
