Philips Atlas of the Universe

Maps of Saturn’s Icy Satellites

A

part from planet-sized Titan, Saturn’s satellites are

small and icy, but they each have their unique charac-

teristics. The eight known before the Voyager missions are

mapped here with data from those missions. The Voyagers

also found eight more satellites, even smaller ones.

MimasThe globe seems to be composed mainly of ice,

though there must be some rock as well. The surface is

dominated by the huge crater now named Herschel, which

is 130 kilometres (80 miles) in diameter – one third the

diameter of Mimas itself – and has a massive central moun-

tain rising to 6 kilometres (nearly 4 miles) above the floor.

There are many other craters of lesser size, together with

grooves (chasma) such as Oeta and Ossa.

EnceladusEnceladus is quite different from Mimas. Craters

exist in many areas, but look ‘young’, and it may be that the

interior is flexed by the pull of the more massive Dione, so

that at times soft ice wells out from below and covers older

formations. There are also ditches (fossae) and planitia

(plains) such as Diyar and Sarandib.

Tethys There is one huge crater, Odysseus, which is

400 kilometres (250 miles) across (larger than Mimas) but

not very deep. The main feature is Ithaca Chasma, a

tremendous trench running from the north pole across the

equator to the region of the south pole. Its average width is

100 kilometres (over 60 miles), and is 4 to 5 kilometres

(about 3 miles) deep, with a rim which rises to half a kilo-

metre (1600 feet) above the outer surface. Other craters

include Penelope, Anticleia and Eumaeus.

DioneDione is much denser and more massive than

Tethys, so that its globe presumably contains less ice and

more rock. The trailing hemisphere is darkish; the leading

hemisphere is bright. The most prominent feature is Amata,

240 kilometres (150 miles) in diameter, which may be either

a crater or a basin, and is associated with bright wispy

ATLAS OF THE UNIVERSE

SELECTED FEATURES

Lat. ° Long. °

MIMAS

Craters

Bedivere 10 N 145

Bors 45 N 165

Gwynevere 12 S 312

Launcelot 10 S 317

Morgan 25 N 240

Chasmata

Avalon 20 – 57 N 160 – 120

Oeta 10 – 35 N 130 – 105

Ossa 10 – 30 S 305 – 280

ENCELADUS

Craters

Dalilah 53 N 244

Dunyazad 34 N 200

Salib 06 S 000

Sindbad 66 N 210

Fossae

Bassprah 40 – 50 N 023 – 345

Daryabar 05 – 10 N 020 – 335

Isbanir 10 S–20 N 000 – 350

Planitia

Diyar 00 250

Sarandib 05 N 300

TETHYS

Craters

Anticleia 30 S 285

Eumaeus 27 N 047

Mentor 03 N 039

Odysseus 30 N 130

Penelope 10 S 252

Chasma

Ithaca 60 S–35 N 030 – 340

180° 150° 120° 90° 60° 30° 0° 330° 300° 270° 240° 210° 180°

-57°

57°

-30°

0° E

30°

S

180° 150° 120° 90° 60° 30° 0° 330° 300° 270° 240° 210° 180°

-57°

57°

-30°

0° E

30°

S

180° 150° 120° 90° 60° 30° 0° 330° 300° 270° 240° 210° 180°

-57°

57°

-30°

0° E

30°

S

W

Mimas

N

W

Enceladus

N

W

Tethys

N

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