Jupiter Archives

May 2, 2023May 2, 2023 by Carolyn Collins Petersen

ESA Can’t Deploy JUICE’s Radar Antenna. It Needs It to Scan Under the Ice at Callisto, Europa, and Ganymede

The Radar for Icy Moons Exploration antenna onboard JUICE after it left Earth. It's still stuck and not yet fully deployed. Courtesy ESA.

In a scene eerily reminiscent of the Galileo spacecraft’s antenna issues, ESA’s Jupiter Icy Moons Explorer (JUICE) is having a problem with an antenna. The 16-meter-long radar Radar for Icy Moons Exploration (RIME) unit is stuck on a tiny pin that’s keeping it from deploying fully.

April 17, 2023April 17, 2023 by Nancy Atkinson

ESA's Juice is On Its Way to Visit Jupiter's Moons

ESA’s Juice mission lifted off on an Ariane 5 rocket from Europe’s Spaceport in French Guiana on April 14, 2023 to begin its eight-year journey to Jupiter, where it will study in detail the gas giant planet’s three large ocean-bearing moons: Ganymede, Callisto and Europa. Credits: ESA - S. Corvaja

A new era of exploration at Jupiter’s moons began last week with the launch of the European Space Agency’s Juice, the Jupiter Icy Moons Explorer. This mission will visit three of Jupiter’s largest moons — Europa, Callisto and Ganymede — to investigate whether they could be potentially habitable, a question that’s been highly debated since the first evidence of subsurface oceans on these moons was seen by the Galileo mission in the 1990s.

March 29, 2023March 29, 2023 by Nancy Atkinson

It's Time For Your Annual Weather Update for the Outer Solar System

Jupiter, as seen by the Hubble Space Telescope in November 2022 and January 2023. Credits: NASA, ESA, STScI, Amy Simon (NASA-GSFC), and Michael H. Wong (UC Berkeley); Image Processing: Joseph DePasquale (STScI).

A couple times a year, the Hubble Space Telescope turns its powerful gaze on the giant planets in the outer Solar System, studying their cloudtops and weather systems. With the Outer Planet Atmospheres Legacy (OPAL) Program, Hubble provides us with these views and also delivers weather reports on what’s happening. Here’s an updated report and some new images of the stormy surfaces of Jupiter and Uranus.

March 4, 2023April 20, 2024 by Nancy Atkinson

Just Dropped: New Close-up Images of Io from Juno, With More to Come

Jupiter's Moon Io, as seen by the Juno spacecraft on Perijove 49 on March 1, 2023, from distances between 52,515 to 64,994 km. Credit: NASA/JPL-Caltech/SwRI/MSSS, processed by Andrea Luck.

On March 1, 2023, NASA’s Juno spacecraft flew by Jupiter’s moon Io, coming within 51,500 km (32,030 miles) of the innermost and third-largest of the four Galilean moons. The stunning new images provide the best and closest view of the most volcanic moon in our Solar System since the New Horizons mission flew past Io and the Jupiter system in 2006 on its way to Pluto.

February 20, 2023February 20, 2023 by Matt Williams

All of Jupiter's Large Moons Have Auroras

Artist's concept of aurorae on Ganymede - auroral belt shifting may indicate a subsurface saline ocean. Credit: NASA/ESA

Jupiter is well known for its spectacular aurorae, thanks in no small part to the Juno orbiter and recent images taken by the James Webb Space Telescope (JWST). Like Earth, these dazzling displays result from charged solar particles interacting with Jupiter’s magnetic field and atmosphere. Over the years, astronomers have also detected faint aurorae in the atmospheres of Jupiter’s largest moons (aka. the “Galilean Moons“). These are also the result of interaction, in this case, between Jupiter’s magnetic field and particles emanating from the moons’ atmospheres.

Detecting these faint aurorae has always been a challenge because of sunlight reflected from the moons’ surfaces completely washes out their light signatures. In a series of recent papers, a team led by the University of Boston and Caltech (with support from NASA) observed the Galilean Moons as they passed into Jupiter’s shadow. These observations revealed that Io, Europa, Ganymede, and Callisto all experience oxygen-aurorae in their atmospheres. Moreover, these aurorae are deep red and almost 15 times brighter than the familiar green patterns we see on Earth.

February 14, 2023February 14, 2023 by Andy Tomaswick

Why are Jupiter’s Trojan Regions so Unevenly Balanced With Asteroids?

Solar systems evolve, especially early on in their lifetimes. While this evolution is primarily driven by gravity, there are some parts of our own solar system that are difficult to understand – especially how gravity forced them into their current configuration. One of the most prominent of these areas is the Trojan asteroids.

February 8, 2023February 8, 2023 by Nancy Atkinson

New Discoveries Puts Jupiter at 92 Known Moons

A top-down overhead view of the orbits of Jupiter's 92 moons. Credit: Scott Sheppard.

The moon hunter strikes again.

A team of astronomers led by Scott Sheppard of the Carnegie Institution has found and confirmed 12 new moons orbiting Jupiter, bringing the total of moons at the giant planet to 92. The new moons were quietly announced on the International Astronomical Union’s Minor Planet Center website last week, and the new discoveries puts Jupiter in the lead in a recent back-and-forth moon battle with Saturn.

Jupiter was solidly in the lead with Sheppard and team’s announcement of 12 new moons back in 2018, but then in 2019, Sheppard and colleagues found a whopping 20 new moons orbiting Saturn, bringing the ringed planet’s total number of moons to 82. But now this latest addition moves Jupiter back in the lead.

With Sheppard around, we may never know the final count.

December 29, 2022December 29, 2022 by Carolyn Collins Petersen

An Ongoing Study of Jupiter’s Cloudtops Has Been Going on for 40 Years

A Hubble Space Telescope image of Jupiter in 2020. Planetary scientists studied temperature changes in its lower atmosphere and may soon be able to predict Jupiter weather. Credit: NASA, ESA, A. Simon (Goddard Space Flight Center), and M. H. Wong (University of California, Berkeley) and the OPAL team.

Some of the most useful discoveries about distant objects take time to complete. For example, several generations of planetary scientists have been studying the clouds of Jupiter since the late 1970s. Their observations focused on the planet’s upper troposphere. The results show unexpected patterns in how the temperatures of Jupiter’s belts and zones change over time.

December 16, 2022March 4, 2023 by Carolyn Collins Petersen

Juno has Been Touring Jupiter’s Moons on its Extended Mission. Next Stop: Volcanic Io

The Juno mission's infrared view of the Jovian moon Io. Taken on July 5, 2022. All the hotspots are volcanic features. Courtesy NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM

For a tiny moon orbiting a giant planet, Io sure packs a giant wallop. It’s the most volcanic world in the solar system. Due to that extreme volcanism, scientists with the Juno mission are now focusing the spacecraft’s instruments and cameras on Io. They want to know more about its eruptions and how its constant stream of material into space interacts with Jupiter’s magnetosphere.

October 14, 2022October 14, 2022 by Andy Tomaswick

New Views of Ganymede and Europa From Earth’s Most Powerful Telescope

Scouting mission locations in the outer solar system is complicated. It is difficult to know what you find before you get there with a probe, and once you’re already there, changing trajectories to look at the most exciting parts of the system is difficult. A much better option would be to map out the system in detail before the probe arrives. That is precisely what a team at the University of Leicester is doing in the expectation of the arrival of the JUICE and Europa Clipper probes to the Jupiter system.