- BBC News World
It is the largest natural satellite in the Solar System.
And now a NASA probe has obtained the closest images of this moon that have so far been achieved.
It is about Ganymede, one of the four moons of Jupiter that Galileo Galilei discovered in 1610.
The Juno probe managed to get close to 1.000 km Ganymede, the closest any ship has been to this giant in more than 20 years.
The photos, captured on June 7, show the surface of Ganymede in great detail, including craters and structures possibly related to tectonic faults.
One of the images that Juno obtained was taken with the JunoCam and the other with the Stellar Reference Unit, two devices installed on the probe.
JunoCam achieved an image of 1 kilometer per pixel, covering almost the entire side of Ganymede, which has ice embedded.
For its part, the Stellar Reference Unit, a navigation camera that maintains the spacecraft’s heading, portrayed the dark side of Ganymede.
This area corresponds to the side opposite the Sun, which is bathed by a dim light which is scattered by Jupiter.
The image of the Stellar Reference Unit is between 600 and 900 meters per pixel, according to NASA.
“This is a different part of the surface seen by JunoCam in direct sunlight,” Heidi Becker, Juno radiation monitoring leader at NASA’s Jet Propulsion Laboratory, said in a statement.
“It will be fun to see what the two teams can rebuild.”
Both pictures show dark and light terrain, remarkably differentiated, in addition to elongated formations that could be related to tectonic plates of the Jovian moon.
In the coming days, Juno plans to send more images, with which it is expected to have more information about the composition of the planet, as well as its ionosphere, magnetósfera and ice cap.
Juno images will also be compared with which it took the Galileo probe between 2005 and 2004, and the Voyager probe in 1979, to see if there has been any change in this period of time.
It is the largest moon in the Solar System and the only one with its own magnetic field, which causes them to form auroras in its atmosphere.
In 2015, NASA’s Hubble Space Telescope found the best evidence to date for an underground ocean of saltwater in Ganymede.
This ocean is believed to have more water than all the water on Earth’s surface.
Ganymede has three main layers. An iron core that generates the magnetic field; a rocky mantle that surrounds the core; and an ice cap surrounding the mantle and core.
For reference, with its 5,268 km in diameter, Ganymede is larger than Mercury.
So far, scientists have confirmed that Jupiter has at least 79 moons, including Ganymede.
The Juno mission
The Juno mission departed on August 5, 2011 and reached Jupiter on July 4, 2016.
It is the probe driven by solar energy who has traveled farther in space.
Its objective is to understand the origin and evolution of Jupiter, the largest planet in the Solar System.
The probe is dedicated to mapping the magnetic and gravitational field of the planet, as well as exploring the swirling clouds that make up its particular atmosphere.
Juno also seeks to identify what Jupiter is made of and what water amount there is in its deep atmosphere.
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Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.