Space · Moons

Thebe

A moon of Jupiter — The second-largest of Jupiter's inner moons — its orbit defines the outer edge of Jupiter's gossamer ring.

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Quick facts

Parent planet

Jupiter

Diameter (mean)

98 km

Mass

4.3 × 10¹⁷ kg
5.85e-06 Moon masses

Mean orbital radius

221,900 km

Orbital period

0.675 Earth days

Discovery year

1979

Discoverer

Stephen P. Synnott (Voyager 1)

Naming origin

Greek nymph, lover of Zeus, namesake of Thebes

Surface conditions

Thebe is an irregularly shaped body 116×98×84 km, the fourth Jovian moon outward and the second-largest of the inner satellites that orbit within the Galilean system. Two large impact craters — Zethus and Antiope — span much of the surface. Like Amalthea, Thebe contributes dust to Jupiter's faint ring system; the Thebe gossamer ring extends just outward from Thebe's orbit.

Stephen Synnott identified Thebe in Voyager 1 images during the March 1979 flyby. The Galileo orbiter returned the only close-resolution imagery during its 2000 flyby.

Missions and observations

Every Jupiter-system mission has had an opportunity to image or characterize Thebe. The list below is the Jupiter-system mission catalog; specific Thebe encounters are documented in mission archives.

Mission	Year at Jupiter	Status
Pioneer 10 NASA	1973	Completed
Pioneer 11 NASA	1974	Completed
Voyager 1 NASA	1979	Completed
Voyager 2 NASA	1979	Completed
Ulysses NASA/ESA	1992	Completed
Galileo NASA	1995	Completed
Cassini-Huygens NASA/ESA/ASI	2000	Completed
New Horizons NASA	2007	Completed
Juno NASA	2016	Active
Europa Clipper NASA	2030	On the way
JUICE ESA	2031	On the way

Naming etymology

Thebe was a nymph in Greek mythology, daughter of the river god Asopus and lover of Zeus, who gave her name to the Greek city of Thebes. The IAU adopted the name in 1983.

Methodology & sources

Diameter, mass, and orbital parameters from JPL Solar System Dynamics — Physical Parameters. Discovery year and discoverer from the JPL Satellite Discovery Circumstances. Naming etymology from the IAU Working Group for Planetary System Nomenclature. Stylized SVG hero composed from NASA / JPL imagery as visual reference; no photographs are reproduced.