You will be able to… •Describe how the physical features of the lunar surface were created. •Explain the history of the moon.

22.3 Earth’s Moon

22.3 Craters

• A crater is the depression at the summit of a volcano or a depression produced by a meteorite impact.

• Rays are any of a system of bright, elongated streaks,

sometimes associated with a crater on the moon.

Formation of a Crater

• This is a view of the Aristarchus and Herodotus craters

taken from orbit during the Apollo 15 mission

Barringer Meteor Crater, Arizona

• Diameter: 1.186 kilometers (.737 miles); age: 49,000 years

22.3 Earth’s Moon Formation

When the solar system was forming, a body the size

of Mars impacted Earth. The resulting debris was

ejected into space, began orbiting around Earth, and

eventually united to form the moon.

22.3 The Lunar Surface

• Most of the lunar surface is made up of densely pitted, light-colored areas known as highlands.

Highlands

Highlands

22.3 The Lunar Surface

• The dark areas on the moon.

• Ancient beds of basaltic lava, originated when asteroids punctured the lunar surface, letting magma bleed out.

• Younger than the Highlands

Maria – Latin for sea

• A rille is a long channel associated with lunar maria. A rille looks similar to a valley or a trench.

Highlands

Maria

22.3 The Lunar Surface

Regolith

• The lunar regolith is a thin, gray layer on the surface of the moon, consisting of loosely compacted, fragmented material believed to have been formed by repeated impacts of meteorites.

The Moon’s Surface

Mare Tranquillitatus

(Sea of Tranquility)

Mare Imbrium

(Sea of Rains)

Kepler

Crater

Copernicus

Crater

Major Topographic Features of the Moon