Jupiter Archives

June 3, 2023June 6, 2023 by Laurence Tognetti

Jupiter’s “Stripes” Change Color. Now We Might Know Why

Infrared images of Jupiter obtained by a ground-based telescope displaying changes in the stripes of Jupiter's clouds between 2001 and 2011 (dashed blue lines). (Credit: Arrate Antuñano/NASA/IRTF/NSFCam/SpeX)

While Jupiter’s Great Red Spot is one of the most well-known spectacles in the solar system, Jupiter’s clouds and stripes that are responsible for the planet’s weather patterns are highly regarded, as well. Though not nearly as visible in an amateur astronomy telescope, Jupiter’s multicolored, rotating, and swirling cloud stripes are a sight to behold for any astronomy fan when seen in up-close images. And, what makes these stripes unique is they have been observed to change color from time to time, but the question of what causes this color change to occur has remained elusive.

May 27, 2023May 27, 2023 by Laurence Tognetti

Juice is Fully Deployed. It’s Now in its Final Form, Ready to Meet Jupiter’s Moons in 2031

Still image from a video animation of the European Space Agency’s (ESA) Jupiter Icy Moons Explorer (Juice) spacecraft. (Credit: ESA/ATG Medialab)

Launched on April 14, 2023, the European Space Agency’s (ESA) Jupiter Icy Moons Explorer (Juice; formerly known as JUICE) spacecraft has finally completed the unfurling of its solar panel arrays and plethora of booms, probes, and antennae while en route to the solar system’s largest planet.

May 16, 2023May 16, 2023 by Nancy Atkinson

Hurray! Juice Deploys its Stuck Antenna

One of the stuck parts of Juice's RIME antenna deploys. Credit: ESA/Juice mission.

ESA’s Juice mission launched last month on April 14, beginning its long journey to explore Jupiter’s icy moons, Ganymede, Europa, and Callisto. But soon after launch, mission controllers realized a 16-meter (52.5 ft)-long antenna for a radar instrument was jammed and couldn’t deploy. The Radar for Icy Moons Exploration (RIME) antenna is mission critical, as it gathers data for the instrument that will be able to map beneath the ice at these moons.

But, whew, the story has a happy ending. After nearly a month of efforts to free the stuck antenna, engineers figured out a fix for the RIME antenna. They fired a mechanical device in the jammed bracket, which created enough jiggling and rattling to allow the antenna to fully deploy.

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.