Space · Moons
Atlas
A moon of Saturn — A flying-saucer-shaped moon — equatorial ridges give Atlas a distinctive UFO silhouette.
Quick facts
Parent planet
Diameter (mean)
30 km
Mass
6.6 × 10¹⁵ kg
9e-08 Moon masses
Mean orbital radius
137,670 km
Orbital period
0.602 Earth days
Discovery year
1980
Discoverer
Richard Terrile (Voyager 1)
Naming origin
Titan condemned to hold up the sky
Surface conditions
Atlas is a flattened, equatorial-ridged moon that looks like a flying saucer in profile — about 41 km across the equator but only 19 km tall. The smooth equatorial ridge is built up from accretion of ring material at the orbit's outer edge of Saturn's A ring. Atlas orbits between the A ring's outer edge and the F ring.
Missions and observations
Every Saturn-system mission has had an opportunity to image or characterize Atlas. The list below is the Saturn-system mission catalog; specific Atlas encounters are documented in mission archives.
| Mission | Year at Saturn | Status |
|---|---|---|
|
Pioneer 11 NASA |
1979 | Completed |
|
Voyager 1 NASA |
1980 | Completed |
|
Voyager 2 NASA |
1981 | Completed |
|
Cassini-Huygens NASA/ESA/ASI |
2004 | Completed |
|
Dragonfly NASA |
2034 | On the way |
Naming etymology
Atlas was the Titan condemned by Zeus to hold up the celestial sphere as punishment for his role in the Titanomachy. Adopted by the IAU 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.