NASA’s Juno mission continues to orbit Jupiter, gathering data on its atmosphere, composition, gravitational field, magnetic field, and radiation environment. This data is helping scientists to learn more about the planet’s formation, internal structure, mass distribution, and what is driving its powerful winds. Periodically, the spacecraft also performs flybys of Jupiter’s largest satellites (the Galilean Moons), acquiring stunning images and vital data on their surfaces. These include optical and thermal images of Io’s many active volcanoes, Europa’s icy terrain, and infrared images of Ganymede.
During its last flyby of Ganymede (June 7th, 2021), Juno collected infrared images and spectra on the moon’s surface using its Jovian InfraRed Auroral Mapper (JIRAM) instrument. According to a recent study by an international team of researchers, this data revealed the presence of salt minerals and organic molecules on the icy moon’s surface. The findings could help scientists better understand the origin of Ganymede, the composition of its interior ocean, and the way material is exchanged between the surface and interior. In short, it could help scientists determine if life exists deep inside Ganymede’s ocean.
The moons of our Solar System have garnered quite a lot of attention in the last few years, especially pertaining to astrobiology and the search for life beyond Earth. From the Galilean moons of Jupiterto the geysers of Enceladus to the methane lakes on Titan, these small worlds continue to humble us with both their awe and mystery. But do the very same scientists who study these mysterious and intriguing worlds have their own favorite moons? As it turns out, seven such planetary geologists were kind enough to share their favorite Solar System moons with Universe Today!
Jupiter is composed almost entirely of hydrogen and helium. The amounts of each closely conform to the theoretical quantities in the primordial solar nebula. But it also contains other heavier elements, which astronomers call metals. Even though metals are a small component of Jupiter, their presence and distribution tell astronomers a lot.
According to a new study, Jupiter’s metal content and distribution mean that the planet ate a lot of rocky planetesimals in its youth.
What is that large dark smudge on Jupiter’s side? It may remind you of a certain scene from the sci-fi film “2010: The Year We Make Contact,” where a growing black spot appears in Jupiter’s atmosphere.
But this is a real photo, and the dark spot is just an elongated shadow of Ganymede, Jupiter’s largest moon. Just like when Earth’s Moon crosses between our planet and the Sun creating an eclipse for lucky Earthlings, when Jupiter’s moons cross between the gas giant and the Sun, they create shadows too.
As originally planned, Juno’s 37th close pass by Jupiter – called Perijove 37 – would have been its last. Per the original mission outline, the Juno spacecraft would have been programed to plunge into Jupiter on Perijove 37 as a mission-ending self-sacrifice. Destroying Juno would protect the Jovian moons — especially Europa — from potential future contamination by an unpowered spacecraft wandering adrift through the Jupiter system. As careful as NASA is about taking precautions to limit the amount of Earth-sourced biological material carried by robotic spacecraft, it’s incredibly difficult to ensure that no microbes might have tagged along.
But, back to Juno: as it stands now, the Juno mission is just getting started. With a mission extension granted earlier this year, Juno will continue to operate until at least 2025, with 42 extra orbits added to the mission.
And thank goodness, because the images from Perijove 37 are pretty stunning. The new mission plan put Juno on a relatively close pass to image Jupiter itself, as well as a great view of Jupiter’s moon Europa, see below.
Many papers are usually released at once for big space exploration missions. Usually, that happens when an entire batch of data has been analyzed. The most recent set of papers is from Juno’s explorations of Jupiter’s atmosphere. With this data dump, scientists now have the first 3D map of the atmosphere of the solar system’s largest planet.
Jupiter’s atmosphere has plenty of distinct features, including lightning and the Great Red Spot. But the underlying processes that drive these features are less well understood, as the physics of the gases that make up Jupiter’s atmosphere is complicated. A team of scientists from all over the globe has found a familiar process in all the chaos, though. They think a process that happens here on Earth might be happening on a grander scale at Jupiter.
One advantage to planetary science is that insights from one planet could explain phenomena on another. We understand Venus’ greenhouse gas effect from our own experience on the Earth, and Jupiter and Saturn share some characteristics. But Jupiter also provides insight into other, farther out systems, such as Uranus and Neptune. Now, a discovery from a spacecraft orbiting Jupiter might have solved a long-standing mystery about Uranus and Neptune – where has all the ammonia gone?
Since the Juno spacecraft has been in orbit around Jupiter for nearly five years — since July 4, 2016 — you may have forgotten about that time back in 2013 Juno flew past Earth. The spacecraft needed a little extra boost to reach Jupiter, so it used Earth for a gravity assist. Image editor Kevin Gill reminded us of that flyby with some stunning newly processed images of Earth, taken by the JunoCam, the “citizen science” camera on board. Pale blue dot indeed!
The Juno mission to Jupiter has been extended to September 2025 – or however long the spacecraft can keep operating around Jupiter.
While Juno has so far focused its attention on the giant planet alone, the mission extension will include observations of Jupiter’s rings and large moons, with targeted observations and close flybys planned of the moons Ganymede, Europa, and Io.
This will be the first close flybys of these moons since the Galileo mission in 1995-2003.