NASA’s Juno spacecraft captured a new view of the irregular moon Thebe during a May 1 flyby, revealing the battered world from just 5,000 km away.
Juno captured this view of Thebe during a close flyby on May 1, 2026. Image credit: NASA / JPL-Caltech.
Thebe is a small, irregularly shaped moon, with dimensions of roughly 116 x 98 x 84 km and a mean radius of about 49 km.
It’s the second-largest of Jupiter’s inner moons and the seventh-largest moon overall in the Jovian system.
Thebe was discovered in 1979 by astronomer Stephen Synnott using images from NASA’s Voyager 1 spacecraft.
It orbits Jupiter at an average distance of about 221,900 km — well inside the orbit of Io, Jupiter’s innermost Galilean moon. One orbit takes roughly 16.1 hours.
Like many inner moons, it is tidally locked, meaning the same face always points toward Jupiter.
Thebe has a heavily cratered, dark reddish surface. Its most prominent feature is the large impact crater Zethus, named after Thebe’s mythological twin brother.
One of Thebe’s most notable contributions is that the moon is the primary source of material for Jupiter’s gossamer ring, one of the faint outer rings in Jupiter’s ring system. Micrometeorite impacts kick dust off the moon’s surface, which then spreads into a diffuse ring along Thebe’s orbital path.
“Thebe resides at the outer edge of Jupiter’s faint ring system and is believed to play a role in the formation of the planet’s ‘gossamer’ ring through the shedding of dust,” NASA scientists said in a statement.
The new image of Thebe was captured with the Stellar Reference Unit (SRU) onboatd the Juno spacecraft from a distance of approximately 5,000 km.
“While the SRU’s primary function is to image star fields for navigation, its high sensitivity in low-light conditions makes it a powerful secondary science instrument,” the researchers said.
“The SRU has previously been used to discover ‘shallow lightning’ in Jupiter’s atmosphere and to image the planet’s ring system.”
