Superb photo of Jupiter’s largest moon marks Juno’s 10th anniversary

Thursday August 5 marked 10 years since NASA sent Juno on a one-way trip to explore the largest planet in our solar system.

The spacecraft did not reach its destination, Jupiter, until July 2016. But NASA nonetheless shared a small gift with all of us, space observers here on Earth, to celebrate the orbiter’s 10 years of service. of Jupiter. This treat, a photo of Jupiter Ganymede’s moon taken on July 20, is a compliment to Juno’s JIRAM, or Jovian Infrared Auroral Mapper.

Ganymede is not correct a cosmic celebrity for being Jupiter’s largest moon. It is also the largest moon in our entire solar system, measuring about one and a half times the size of Earth’s moon. Just under half of its water-ice-covered surface is dark and dotted with impact craters, according to NASA. The rest is lighter in color and marked by grooved terrain.

You can’t see a lot of fine detail in this new image, but that’s because of the source. Juno’s JIRAM is an infrared camera, and the image above is a composite taken from three separate moon flyovers, the last of which occurred on July 20. The composite is not intended to capture fine surface detail; rather, it offers a view of “the icy shell of Ganymede and the composition of the ocean of liquid water below”.

The unique features of the moon’s surface are much easier to spot in more traditional photos. This one, captured on June 7, gives us Juno’s view of Ganymede during the closest flyby of the moon by any spacecraft in the past 20 years. You can clearly see the intricate grooved terrain here, which may or may not be the result of tectonic fault lines.

Obviously, the 10-year-old Juno wasn’t there on the previous closest flyby. The Jupiter orbiter is the second spacecraft to visit the Moon and the gas giant it orbits, after the Galileo probe.

The next big moment for Juno will be in September 2022 when the probe sets up for a close examination of the moon in Jupiter, Europe, with a flyby of the Io moon to follow a year later. All of this, including these new 10th anniversary images, represents extra time for the solar-powered probe. NASA has officially extended Juno’s mission to 2025 “or end of life” in January 2021.

Probes like this are not intended for salvage. Juno’s work will come to an end with its destruction, when Jupiter’s enormous gravitational pull brings the spacecraft close enough to tear it apart.