The 4 largest moons of Jupiter aren’t simply blurry smudges in Galileo’s telescope anymore.
The Italian astronomer Galileo Galilei found Ganymede, Callisto, Europa and Io again in 1610, which explains why they’re referred to as the Galilean moons. We have realized so much about these unique our bodies prior to now 400 years due to ever-improving telescope views and close-up imagery snapped by voyaging spacecraft like NASA’s Juno Jupiter orbiter.
Certainly, Juno lately carried out two shut flybys of Io, probably the most volcanically lively physique within the photo voltaic system, and knowledge from the encounters is wowing scientists.
Associated: NASA’s Juno probe sees lively volcanic eruptions on Jupiter’s volcanic moon Io (photos)
“Io is just affected by volcanoes, and we caught just a few of them in motion,” Scott Bolton, Juno’s principal investigator, stated in a NASA assertion on Thursday (April 18).
“We additionally acquired some nice close-ups and different knowledge on a 200-kilometer-long (127-mile-long) lava lake referred to as Loki Patera,” Bolton added. “There’s superb element displaying these loopy islands embedded in the course of a probably magma lake rimmed with sizzling lava. The specular reflection our devices recorded of the lake suggests elements of Io’s floor are as clean as glass, harking back to volcanically created obsidian glass on Earth.”
Juno got here inside about 930 miles (1,500 kilometers) of Io’s roiling floor throughout the two flybys, which occurred in December 2023 and February 2024. Mission group members processed the encounter knowledge right into a flyover animation, which gives a blinding view of the moon.
Maps created with Juno knowledge lately even have proven that Io’s floor is smoother than these of the opposite Galilean moons, and that Io’s poles are colder than its mid-latitude areas, mission group members stated.
Jupiter, too
Juno has additionally collected intriguing details about the poles of Jupiter lately utilizing its Microwave Radiometer (MWR) instrument, together with variations among the many fuel large’s intriguing north polar cyclones.
“Maybe [the] most placing instance of this disparity could be discovered with the central cyclone at Jupiter’s north pole,” Steve Levin, Juno’s venture scientist at NASA’s Jet Propulsion Laboratory in Southern California, stated in the identical assertion.
“It’s clearly seen in each infrared and visual gentle photos, however its microwave signature is nowhere close to as robust as different close by storms,” Levin added. “This tells us that its subsurface construction have to be very completely different from these different cyclones.”
The Juno group can also be studying extra about Jupiter’s water abundance. The scientists aren’t on the lookout for flowing lakes and rivers — Jupiter has no discernible floor, in spite of everything — however slightly for oxygen and hydrogen molecules in its thick environment. Such work follows on from that accomplished by NASA’s Galileo Jupiter orbiter, which ended its mission with an intentional demise dive into Jupiter’s environment in 1995.
Galileo “did superb science, however its knowledge was up to now afield from our fashions of Jupiter’s water abundance that we thought-about whether or not the placement it sampled could possibly be an outlier. However earlier than Juno, we could not verify,” Bolton stated. “Now, with latest outcomes made with MWR knowledge, now we have nailed down that the water abundance close to Jupiter’s equator is roughly three to 4 occasions the photo voltaic abundance when in comparison with hydrogen. This definitively demonstrates that the Galileo probe’s entry website was an anomalously dry, desert-like area.”
Whereas there are nonetheless many questions surrounding how Jupiter fashioned, scientists proceed to depend on knowledge coming in from Juno’s prolonged mission. The probe’s subsequent shut flyby of Jupiter — its 61st total — shall be on Might 12.
