The Earth’s The Earth’s MoonMoon

SatellitesSatellites

Definition: Any Definition: Any body that body that orbitsorbits a a larger bodylarger body

1957: First 1957: First artificial satellite, artificial satellite, Sputnik,Sputnik, launched launched by the Sovietsby the Soviets

Earth’s only Earth’s only naturalnatural satellite satellite is the moon.is the moon.

The MoonThe Moon

Force of gravity is 1/6th that of Force of gravity is 1/6th that of Earth’s. Earth’s.

Because of less gravity, it has no Because of less gravity, it has no atmosphere; therefore it has no atmosphere; therefore it has no weatherweather

Lack of atmosphere also means Lack of atmosphere also means that there is a huge temperature that there is a huge temperature range: 134 degrees C in the day, range: 134 degrees C in the day, -170 degrees C at night-170 degrees C at night

The MoonThe Moon

Your weight would change, but Your weight would change, but not your mass!!not your mass!!

1969-1972: The US sent 6 1969-1972: The US sent 6 ApolloApollo missions to the moon missions to the moon

Moon rotates once every 27.3 Moon rotates once every 27.3 days, but appears to take 29.5 days, but appears to take 29.5 days.days.

Venus is 100 times more distant Venus is 100 times more distant than the moon!than the moon!

Click here to see an Apollo 11 Click here to see an Apollo 11 panoramapanorama

The Lunar SurfaceThe Lunar Surface

Maria: dark areas on the moon; Maria: dark areas on the moon; made of solidified lavamade of solidified lava

Highlands: light areasHighlands: light areas Craters: bowl-shaped Craters: bowl-shaped

depressions, most from the depressions, most from the moons early formation; named moons early formation; named for famous scientistsfor famous scientists

Rays: streaks that extend from Rays: streaks that extend from the impact sitesthe impact sites

Maria

Click here for a crater pic and explanation

Rayed crater Copernicus

Rayed crater Tycho

Lunar RocksLunar Rocks

Most of the surface is covered in Most of the surface is covered in regolithregolith (layer of dust and rock) (layer of dust and rock) from meteorite impactfrom meteorite impact

Moons rocks are similar to Earth Moons rocks are similar to Earth rocksrocks

Interior of the MoonInterior of the Moon

Less dense than the interior of Less dense than the interior of the Earththe Earth

Crust is thinner on the Earth-Crust is thinner on the Earth-facing sidefacing side

Beneath the crust is the mantle Beneath the crust is the mantle (silica, iron and magnesium); (silica, iron and magnesium); lower portion may be moltenlower portion may be molten

May have a small iron coreMay have a small iron core

Where did the moon come Where did the moon come from, anyway?from, anyway?

Giant impact theory: formed Giant impact theory: formed when a Mar-sized object struck when a Mar-sized object struck the Earththe Earth

Fragments ejected from the Earth Fragments ejected from the Earth (mostly less dense crust and (mostly less dense crust and mantle)mantle)

Supported by moon rockSupported by moon rock Explains why the moon is less Explains why the moon is less

dense than the Earthdense than the Earth

Where did the moon come Where did the moon come from, anyway?from, anyway?

2nd phase: moon was covered 2nd phase: moon was covered with molten lava – densest with molten lava – densest material moved to the centermaterial moved to the center

3rd phase: meteorite impact 3rd phase: meteorite impact “punches” through thin crust; “punches” through thin crust; liquid rock seeps throughliquid rock seeps through

Current phase: less loose Current phase: less loose material in solar system; only material in solar system; only rayed craters formrayed craters form