Phoebe was first discovered back in 1899.  The moon is irregular with approximate dimensions of 219×217×204 km, averaging to about 213 km (132 miles) across, and orbits Saturn every 18 months or so (550.6 days) at a distance of 12,955,759 km.  The orbit is moderately eccentric.  It spins on its axis once every 9 hours and 17 minutes or so.  Phoebe's characteristics, for example the high rock content compared to the inner satellites, indicate that it may be a captured Centaur.  It is very heavily cratered, some as much as 80 km (50 miles) across.  Phoebe is associated with the Phoebe Ring, a huge but incredibly tenuous ring that lies outside of the main ring system. 

The pictures below show how heavily cratered Phoebe is, as well as highlighting some of the larger, named craters.  The craters are named for the Argonauts, Greek mythological explorers who, lead by Jason, searched for the golden fleece.  The largest crater is called Jason, and is about 100 km (62 miles) across.

Phoebe is the largest of the Norse Group of some 39 known moons, most of which are very small.  The group is divided further into several sub groups.  These are all the moons in the group that have been formally named, with brief details.  Note that all values are rounded to one decimal place. 
WILLIAM & DEBORAH HILLYARDWILLIAM & DEBORAH HILLYARD

Solar System -

Saturn's Moons

Phoebe (& The Norse Group)



Name

Diameter
Orbit
million km

Period
Suttungr 5.6 km 19.7 1,029.7 days
Hati 6.0 km 20.3 1,080.1 days
Greip 5.0 km 18.1 906.6 days
Jarnsaxa 6.0 km 18.6 943.8 days
Mundilfari 5.6 km 18.4 928.8 days
Thrymr 5.6 km 20.8 1,120.8 days
Aegir 6.0 km 19.6 1,025.9 days
Fenrir 4.0 km 22.5 1,260.0 days
Surtur 6.0 km 22.2 1,238.6 days
Ymir   18.0 km 23.0 1,315.1 days
Loge 6.0 km 23.1 1,314.4 days
Fornjot 6.0 km 23.6 1,354.0 days

Name

Diameter
Orbit
million km

Period
Skathi subgroup
   Skathi 6.4 km 15.6 725.8 days
   Skoll 6.0 km 17.6 869.0 days
   Hyrrokkin 8.0 km 18.2 914.3 days
   Bergelmir 6.0 km 19.4 1,006.7 days
   Farbauti 5.0 km 20.3 1,079.1 days
   Kari 7.0 km 22.3 1,243.7 days
Narvi subgroup
   Narvi 6.6 km 19.4 1,006.5 days
   Bestla 7.0 km 20.2 1,088.0 days

Phoebe
Phoebe's
Craters
Some of the other moons in the Norse Group
Saturn's moons are grouped as follows.  Select to see details of the moon or the group of moons:


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