Page 53 - Ultimate Visual Dictionary (DK)

NEPTUNE AND PLUTO

EXTERNAL FEATURES AND INTERNAL COMPOSITION
Cloudtop
temperature Atmosphere STRUCTURE OF NEPTUNE OF ATMOSPHERE
-360°F (-220°C) merging into Hydrogen 85%
mantle
Helium 13%
Mantle 6,000 to
9,000 miles (10,000 Methane 2%
to 15,000 km) thick
Adams ring
Haze of hydrocarbons
above clouds
Le Verrier ring
Atmosphere of
hydrogen,
helium, and
methane gases

Mantle of icy
water, methane,
and ammonia
Lassell
Rocky silicate core ring
8,700 miles (14,000
km) in diameter Galle ring

Darker clouds of
hydrogen sulfide
below main cloud
deck

Main cloud deck
blown by winds up to
1,200 mph (2,000 km/h)
Great Dark Spot Methane cirrus clouds
25 miles (40 km) Surface of icy
above main cloud deck water and methane
Small Dark Spot
Scooter
Icy mantle
TILT AND ROTATION OF PLUTO EXTERNAL FEATURES AND
INTERNAL STRUCTURE
OF PLUTO
Axial tilt
of 57.5° Surface of water ice
and methane ice Core of rock and,
possibly, ice
One rotation
takes 6 days
North Pole and 9 hours
Surface temperature
Tenuous about -360°F (-220°C)
atmosphere forms
Orbital plane
when Pluto is at its
closest to the Sun
COMPOSITION
OF TEMPORARY
Perpendicular Axis of ATMOSPHERE
to orbital plane Methane probably mixed with nitrogen
South Pole rotation
and carbon monoxide 100%
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