PHYS
205
The
Moon
PHYS
205
Basic Properties
• Mass: 0.012 Earth
• Diameter: 3476 km
• Density: 3.2 gr/cm3
• Gravity: 0.17 Earth
• Surface Reflectivity: 12%
PHYS
Lunar Interior:
205
PHYS
205
Lunar Surface
• Highlands: higher than the surroundings,
heavily createred, 4.4 billion years old.
• Seas: maria, 17%, less cratered, roughly
circular in shape, composed of basalt, 3.3-
3.8 billion years old, impact basins
• Mountains: ridges of craters
• Geologically dead for the past 3 billion
years.
PHYS
Lunar Maria:
205
PHYS
205
Meteor Crater in Arizona
PHYS
205
Mannicougan Crater
PHYS
205
Impact
Cratering:
PHYS
205 Mare Imbrium and Crater Copernicus
PHYS
205
M Messenger of the
e Gods, Hermes.
r The God of
commerce and
c travel.
u Very bright,
appears shortly
r after sunset of
right before
y sunrise.
PHYS
205
Basic Properties:
• Distance from the Sun: 0.39 AU
• Mass: 0.055 Earth
• Diameter: 4878 kms
• Density: 5.43 gr/cm3
• Surface Gravity: 0.38 Earth
• Surface Reflectivity: 13%
• Revolution period: 88 days
• Rotation period: 59 days
PHYS
205 Rotation of Mercury
• Revolution period:
88 days
• Rotation period:
59 days
• 700K at noon, 100K
at dawn -> surface
cracks.
• Most of the info
we have comes from
Mariner 10 (1974).
PHYS
205 Mariner 10
PHYS
205
The Interior of Mercury:
Density: 5.44 g/cm3
Crust: Mostly rocky,
700 kms thick.
Core: Liquid, iron –
sulfur
Magnetic field is 1%
of the Earth.
PHYS
205 Surface of Mercury
• Heavily cratered,
craters named after
artists (Bach,
Shakespeare, Tolstoy,
etc.)
• Large Caloris basin
similar to the Lunar
Maria.
• Surface no longer
active.
PHYS
205
Double Ring Basin
PHYS
205 Mercury Surface Cracks
PHYS
205
Polar Ice on Mercury
• No seasons on Mercury.
• Polar regions are very cold.
• Polar regions have high
reflectivity suggesting that
there is polar ice.