Space · Moons

Sinope

A moon of Jupiter — For 86 years the outermost known moon of Jupiter — Nicholson's first Jovian discovery.

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Quick facts

Parent planet

Jupiter

Diameter (mean)

38 km

Mass

7.5 × 10¹⁶ kg
1e-06 Moon masses

Mean orbital radius

23,939,000 km

Orbital period

758.9 Earth days

Discovery year

1914

Discoverer

Seth Barnes Nicholson

Naming origin

Greek nymph who tricked Zeus

Surface conditions

Sinope is a 38-km dark retrograde irregular moon. From its 1914 discovery until 2000, Sinope was the outermost confirmed moon of Jupiter; the more-distant retrogrades discovered since are all smaller and orbit even farther out. Sinope's orbit is highly inclined and eccentric, suggestive of capture rather than co-formation with Jupiter.

Missions and observations

Every Jupiter-system mission has had an opportunity to image or characterize Sinope. The list below is the Jupiter-system mission catalog; specific Sinope 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

Sinope was a nymph who tricked Zeus into granting her perpetual virginity. The IAU adopted the name in 1975.

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.