The Moon Satellite – Any body orbiting a central mass No Atmosphere No temperature regulation Daytime temperature = 400 K (266 F) Nighttime temperature = 100 K (-280 F)

Moon Facts: Moons Period days Moons Day days Distance- 250,000 miles Gravity- 1/6 th that of the earth’s. 120 pound weight on the earth would weigh about 20 pounds on the Moon.

Atmosphere of the Moon The moon has no atmosphere Not really. About half of the present atmosphere of the Moon is from the exhaust of the Apollo Moon Missions! Therefore, there is no weather on the moon. No atmosphere means that wings (airplanes, helicopters, etc.) and parachutes won’t work. It also means that there is essentially no protection from x-rays and micrometeorites on the Moon’s surface as there is on the earth.

Surface Features Craters: Mare - Dark, smooth lava filled regions Highlands - lighter colored, rough terrain Mountains - actually crater rims or sections of crater walls Volcanic features

Mare tend to have circular edges large impact basins that filled with lava

Areas without mare Heavily cratered highlands

Impact made basin (bowl shape) Lava filled basin creating mare Later impacts occurred Mare are younger (newer) than highlands

Rille Faults

Structure of the Moon Composition of the Moon similar to the Earth’s Mantle Very little metal (iron, nickel), mainly rock Iron-rich core Mantle Crust

Lunar Crust Near sideFar side

Thinner crust on Near Side allows formation of Mare

Gravity of the Moon The earth’s gravity pulls the moon and keeps it in orbit. (Without its motion, the moon would fall down to the earth. Without the earth’s gravity, the Moon’s motion would cause it to leave the earth.) Does the Moon’s gravity pull on the earth? Are there any effects that we can see if the Moon does in fact pull on the earth?

Gravity of the Moon – Tides What are tides, and what causes tides? Are some tides bigger than others? Is it in any way related to either the sun or the Moon? We will try to answer the first question AFTER we answer the other three.

Tides: Caused by the gravitational interaction between the Earth and the Moon. The gravitational attraction of the moon causes the oceans to bulge out in the direction and opposite direction of the moon.

Spring Tides: Spring tides- Strong Tides occur when the Earth moon and sun align (has nothing to do with the season Spring)

Neap Tides: Neap tides- Weak tides that occur when the gravitational forces of the Moon and the Sun are perpendicular to one another

Tidal Effects The Earth’s pull slowed the rotation of the Moon (Tidally locked) The Moon’s pull is slowing the rotation of the Earth (by about 0.7 seconds/year) The Earth’s pull in also slowing down the Moon’s orbital velocity - the Moon is getting further from the Earth by 3.8 cm/year Far in the future, the Moon will be very far from us, one side of the Moon will face one side of the Earth

Apollo Mission 6 lunar landings 12 people walked on the Moon (and played golf) 850 pounds of rocks

All near side landings Lunar Rover

Lunar Rocks Basalts - found in the mare, volcanic Anorthosites - highlands, aluminum, calcium, silicates Breccia - cemented rocks

Origin of the Moon History of the Moon: - Impact Theory- 4.5 billion years ago A very large asteroid hit earth with enough force to break a chunk of earth off which was caught in the earths orbit and became the moon. - Moon has a similar mantle composition as earth