The European Space Agency’s Juice spacecraft recently made a flyby of both Earth and the moon on its way to Jupiter. The purpose of the flyby was mainly to adjust the spacecraft’s speed and direction, to help send it on its long journey to investigate Jupiter and its icy moons. But as the spacecraft flew within a few thousand miles of the Earth’s surface, it was able to use its instruments to snap pictures of both the Earth and the moon.
The Juice spacecraft’s main camera is called Janus, which will take high-resolution images of Jupiter’s moons to identify surface features, as well as observing the clouds of Jupiter. The flyby gave the opportunity to test this instrument on both the moon, which has no atmosphere and is so comparable to the moons of Jupiter, and the Earthm which has a cloud layer that can serve as a stand-in for the thick atmosphere of Jupiter.
“After more than 12 years of work to propose, build and verify the instrument, this is the first opportunity to see first-hand data similar to those we will acquire in the Jupiter system starting in 2031,” said Pasquale Palumbo of the National Institute for Astrophysics in Rome and principal investigator of the Janus team, in a statement translated from Italian. “Even though the flyby was planned exclusively to facilitate the interplanetary journey to Jupiter, all the instruments on board the probe took advantage of the passage near the moon and Earth to acquire data, test operations and processing techniques with the advantage of already knowing what we were observing.”
The images show the kinds of detail that the Janus camera is able to pick up, with the views of the moon’s surface a particular highlight. The researchers didn’t only take pictures, though — they also performed tests like deliberately blurring images to test out their algorithms, which are designed to restore lost or corrupted data. They also took images using different settings and time intervals, to see in practice what data the different options gave them.
Juice is now continuing on its long journey, set to arrive at Jupiter in 2031. More images from the flyby can be found on the European Space Agency website.
