The Moon

moon

a body that is smaller than a planet and orbits the planet

satellite

a object in orbit around a body with a larger mass

Sputnik I

Soviets in 1956

Explorer I

1st satellite launched by the US

6 Apollo spacecrafts

the number of Apollo spacecrafts the US sent to the moon between 1969-1972

moon’s gravity

not strong enough to hold gases so there is no atmosphere

134 °C

daytime temperature on the moon’s surface

-170 °C

nighttime temperature on the moon’s surface

27.3 days

moon’s rotational period around Earth

29.5 days

the number of Earth days 1 lunar day is on the moon

240,000 miles

distance from Earth to the moon

light areas

rough highlands composed of light colored rock (hills)

Maria

dark areas that are smooth and reflect little light (once lava)

Rilles

long, deep channels that run through the Maria (looks like dry riverbeds)

craters

bowl shaped depressions formed 4 billion years ago, from debris when solar system was formed

large craters

named for famous scholars and scientists (ex: Tycho and Copernicus), in addition to millions of smaller craters

ray

when crater forms, the displaced material settled in streaks that extend outward

seismographs

used to figure out information about the interior of the moon

60 km

depth of the crust

1000 km

thickness of the mantle

iron

makes up the core

1st stage of moon development

Mars sized body struck Earth and collision ejected a fragment into orbit, most of the material ejected was Silica-rich

2nd stage of moon development

surface of the moon covered by an ocean of hot molten rock, materials separated by density (Ti, Mg, Fe)

lunar rocks

meteorites strike the moon and crush much of the rock into dust and small fragments

Regolith

almost all of the surface is covered by this dust and rock that is 1m-6m thick

igenous rock

near the surface (O, Si)

lunar highlands

course-grained rock (Ca, Al)

basalts

found in Maria (Ti, Mg, Fe)

3rd stage of moon development

outer surface cooled and formed thick, solid crust; being struck by debris (craters); some meteorites broke through crust and molten rock and escaped, forming maria

most recent moon development stage

virtually all activity has stopped because of cooling