Page 50 - Ultimate Visual Dictionary (DK)

THE UNIVERSE

Uranus TILT AND ROTATION OF URANUS
Axial tilt
of 97.9° Perpendicular to
orbital plane
URANUS IS THE SEVENTH PLANET from the Sun
and the third largest, with a diameter of about
32,000 miles (51,000 km). It is thought to Orbital
consist of a dense mixture of different types of plane South Pole
ice and gas around a solid core. Its atmosphere
contains traces of methane, giving the planet a
blue-green hue, and the temperature at the cloud
FALSE-COLOR Axis of
IMAGE OF URANUS tops is about -350°F (-210°C). Uranus is the most
rotation
featureless planet to have been closely observed:
only a few icy clouds of methane have been seen so far. Uranus is
North One rotation
unique among the planets in that its axis of rotation lies close to its Pole takes 17 hours
orbital plane. As a result of its strongly tilted rotational axis, Uranus rolls and 14 minutes
on its side along its orbital path around the Sun, whereas other planets spin
more or less upright. Uranus is encircled by main rings that consist of rocks
interspersed with dust lanes and two distant outer rings made of dust. The
rings contain some of the darkest matter in the solar system and are extremely MAJOR MOONS
narrow, making them difficult to detect: most of them are less than 6 miles (10 km)
wide, whereas most of Saturn’s rings are thousands of miles in width. There are
27 known Uranian moons, all of which are icy and most of which are farther out
than the rings. The 13 inner moons are small and dark, with diameters of less
than 100 miles (160 km), and the five major moons are between about 290 and
1,000 miles (470 and 1,600 km) in diameter. The major moons have a wide variety
of surface features. Miranda has the most varied surface, with cratered areas
broken up by huge ridges and cliffs 12 miles (20 km) high. Beyond these are nine
MIRANDA
much more distant moons with diameters less than 90 miles (150 km). Diameter: 295 miles
Average distance from
planet: 80,700 miles
RINGS OF URANUS

Epsilon ring
Lambda ring

Delta ring
RINGS AND DUST LANES ARIEL TITANIA
Gamma ring Diameter: 720 miles Diameter: 981 miles
Average distance from Average distance from
planet: 118,800 miles planet: 270,900 miles
Eta ring
Beta ring

Alpha ring

Rings 4 and 5

Ring 6 UMBRIEL OBERON
Diameter: 726 miles Diameter: 946 miles
Average distance from Average distance from
Zeta ring
planet: 165,500 miles planet: 362,000 miles