Transcript Lunar Structure - Cloudfront.net

The Moon Itself
Structure and
Atmosphere
Basic Lunar Stats
Radius: 1,738 km ( 26 % of Earth’s)
Mass: .0123 Earth Masses (7.349 x 10^22 kg)
Density: 3.34 g/cm³
Surface Gravity: 1.6 m/s² (1/6 of Earth’s)
Temperature: Low: -173ºC (-280ºF)
(Perhaps -240°C ( -400°F) in deep craters)
High: 130°C (260°F)
Orbital Radius: 384,400 km (240,000 miles)
The Lunar Atmosphere
For all practical purposes the Moon has no
atmosphere.
The lack of an atmosphere is why temperatures
vary so greatly…no greenhouse effect
There is slightly more helium near the Moon’s
surface than in space, but not enough to count
as an atmosphere. Near the poles there are
traces of hydrogen.
Source? Frozen Water from comets that has
collected in the inside of polar craters that are
permanently dark and thus cold.
Water Ice Confirmed on Moon
In November 2009 a space probe was delibrately
crashed into a crater near the Moon’s South
Pole.
Another probe flew through the resulting “splash”
of debris and confirmed the presence of water
ice!
The Regolith
Collisions of asteroids and meteoroids
with the moon have created the
Regolith
It is a light colored layer of dust and rock
Lunar Layers
Regolith: Tens of
meters thick.
Crust: made of
Silicates, rigid
60 km thick on near
side.
100 km on far side.
Mantle: about 1300km
thick. Denser than
crust, but rigid
Core: Metallic, Iron The core is off center…closer to near
side.
and Nickel, very
Earth’s gravity affects core and crust.
small.