Image: Wikimedia Commons

Janus

Moon of Saturn

Moonmoon of Saturn shepherd moon regular moonQ17754

Also known as Saturn X · S/1966 S 2 · S/1979 S 2 · S/1980 S 1 · S/1980 S 2

Orbits: Saturn
Mass: 1.9 zettagram
1
Sources
1.ssd.jpl.nasa.gov/?sat_phys_parRetrieved 2020-09-05
View statement on Wikidata ↗
Orbital period: 0.6947 days
Semi-major axis: 151,500 km
Discovered by: Audouin Dollfus
Discovered: December 15, 1966

Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

Janus is an inner satellite of Saturn. It is named after the mythological Janus, the Roman god of beginnings. This natural satellite was first identified by Audouin Dollfus on December 15, 1966, although it had been unknowingly photographed earlier by Jean Texereau. Further observations led to the realization that Janus shares a unique orbital relationship with another moon, Epimetheus. The discovery of these two moons' peculiar co-orbital configuration was later confirmed by Voyager 1 in 1980.

Overview

All data

29 statements · 17% with external sources · numbers in brackets are citations

Named after: Janus
Albedo: 0.71 criterion used: geometric albedo
1
Sources
1.Stated in Enceladus: cosmic graffiti artist caught in the act.
View statement on Wikidata ↗
Eccentricity: 0.0068
Inclination: 0.163 degree
Diameter: 178 km
Density: 0.6413 g/cm³ temperature: 76 K
Surface gravity: 0.017 metre per square second
Name: Saturn X

On other databases

12 identifiers linking Janus across the web's reference databases

Data quality

statements

17%

externally sourced

Source last edited September 21, 2026. AIDB refreshes this page daily.

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AIDB. (2026). Janus (Q17754). Retrieved from https://aidb.si/e/janus-Q17754