![]() |
Explanation: These two moons change places. Epimetheus and Janus, two small moons of Saturn, actually switch positions as they orbit their home planet. The orbital radii of the moons are strangely separated by less than the radii of the moons themselves: about 50 kilometers. One moon orbits Saturn well ahead of the other, at first. As the two moons gravitationally attract, they approach each other and, every few years, actually pass and trade orbits. This strange dance creates speculation that Epimetheus and Janus were once joined and later split from each other. Pictured above, the two moons were photographed rounding their orbits just outside of Saturn's F ring. The above image was taken in early September by the robot Cassini spacecraft, also orbiting Saturn.
January February March April May June July August September October November December |
|
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: Epimetheus - Janus - Saturn
Publications with words: Epimetheus - Janus - Saturn
See also:
- APOD: 2025 September 25 B Saturn Opposite the Sun
- APOD: 2025 September 22 B Equinox at Saturn
- APOD: 2025 February 23 B Saturn in Infrared from Cassini
- APOD: 2024 December 8 B Aurora around Saturns North Pole
- Saturn at Night
- APOD: 2024 August 27 B Moon Eclipses Saturn
- APOD: 2024 June 23 B The Colors of Saturn from Cassini