Side-by-side Jupiter images show James Webb's infrared prowess. It spots auroras, rings, and faint galaxies Hubble can't see clearly.
- NASA released new snaps of Jupiter taken by the James Webb Space Telescope in August.
- The Hubble Space Telescope has also taken Jupiter images, but Webb reveals details Hubble couldn't see.
While the Hubble Space Telescope has been snapping gorgeous photos of Jupiter for decades, new Jupiter images taken by the James Webb Space Telescope in August, invite comparison. Studied side by side, Webb's shots reveal stunning new details of the gas giant that Hubble couldn't detect.
"JWST isn't giving us something clearer than Hubble here, but it is giving us something different," James O'Donoghue, a planetary scientist from the Japan Aerospace Exploration Agency, told Insider. "I think of JWST as giving us an extra sense."
Often described as the successor to Hubble, Webb launched on December 25, 2021, after more than two decades of development. Since that time, the $10 billion telescope has traveled more than 1 million miles from Earth and is now stationed in a gravitationally stable orbit, collecting infrared light and peering at objects whose light was emitted more than 13.5 billion years ago, which Hubble can't see. This is because this light has been shifted into the infrared wavelengths that Webb is specifically designed to detect.
The result: Compared to Hubble, Webb offers sharper and crisper images, and new details of Jupiter's auroras, storm systems, rings, and tiny moons.
Webb's infrared lens captures Jupiter's glowing auroras in greater detail than Hubble
Webb captured the new Jupiter images using its Near Infrared Camera (NIRCam), which translates infrared light into colors the human eye can see. The image of Jupiter taken by Webb, above right, was artificially colored to make specific features stand out. Red coloring highlights the planet's stunning auroras, while light reflected from clouds appears blue. Jupiter's Great Red Spot — an enormous storm that has been swirling for centuries — is so bright with reflected sunlight that it appears white.
The Hubble Space Telescope can also spot spot Jupiter's auroras when capturing ultraviolet light. In the above left image, Hubble captured optical observations of the planet's northern lights in a composite.
Still, Webb's infrared image shows the auroras in greater detail, lighting up both the planet's poles.
Auroras are colorful displays of light that are not unique to Earth. Jupiter has the brightest auroras in the solar system, according to NASA. On both Earth and Jupiter, auroras occur when charged particles, such as protons or electrons, interact with the magnetic field — known as the magnetosphere — that surrounds a planet. Jupiter's magnetic field is about 20,000 times stronger than Earth's.
In his research, O'Donoghue studies Jupiter's upper atmosphere, several thousand miles above the clouds you can see in visible images. "With JWST, we can see Jupiter's infrared auroras in the extended upper atmosphere above the planet," O'Donoghue said.
While Hubble can spot Jupiter's auroras when capturing ultraviolet light, Webb's infrared image shows the auroras in greater detail.
"I've never seen anything like that before," O'Donoghue said, adding, "I can't quite believe we've got that shot from such a vast distance. It really speaks to how effective JWST is at picking up faint light."
Looking at Jupiter in infrared, Webb spots tiny moons Hubble can't pick out as easily
Webb's new images of Jupiter show two of the planet's moons, Amalthea and Adrastea. Adrastea, the smaller of the two, measures just 12 miles across, according to NASA. In comparison, Hubble's image of Jupiter shows the planet's ocean-filled moon, Europa, which measures 1,940 miles across.
Astronomers believe Europa's ocean makes it a promising place to look for life within our solar system.
Webb has captured images of icy Europa, which were released in July, but the new snapshot is taken at an angle where Europa cannot be observed. Instead, Webb's new Jupiter image showcases two smaller, fainter moons which can be seen more clearly in infrared. Jupiter has 79 moons, according to NASA.
"This is one of my favorite images of Jupiter of all time," O'Donoghue said.
Webb also spotted Jupiter's thin rings, which are made of dust particles formed when cosmic debris smashed into four of Jupiter's moons — including Amalthea, which is also pictured in the newly released images.
"The JWST image is, of course, stunning," Luke Moore, an astronomer at Boston University, told Insider. "Particularly, the level of spatial detail is impressive in the infrared — due to JWST's large primary mirror — and the contrast is incredible, as you can see the incredibly faint rings, as well as the much brighter planet."
Webb gathers light from faraway galaxies that Hubble can't capture
The fuzzy spots lurking at the bottom of the frame in Webb's image are likely galaxies "photobombing" Webb's image of Jupiter, according to NASA. Those faint galaxies are hidden in Hubble's snap of Jupiter, in which the planet — and its moon Europa — are seen against an inky black expanse.
Because of Webb's ability to gather infrared light, which is invisible to the human eye, it is able to cut through cosmic dust and see far into the past. One of the new telescope's main goals is to find galaxies so distant that their light travels almost the entire history of the universe to reach Webb. NASA says Webb is able to peer farther than other telescopes, like Hubble, capturing images of extremely faint galaxies that emitted their light in the first billion years or so after the Big Bang.