20-2a pgs. 549 – 550

IN: How do you think our moon formed?

Satellites – natural or artificial bodies that revolve around large bodies like planets.

Earth’s moon is also called Luna. All planets have moons except

Mercury and Venus.

The United States achieved the first manned landing on Earth's Moon as part of the Apollo 11 mission commanded by Neil Armstrong.

On July 20, 1969, Armstrong, accompanied by Edwin 'Buzz' Aldrin, landed the lunar module Eagle on the surface of the Moon.

Armstrong and Aldrin spent a day on the surface of the Moon before returning to Earth.

A total of six such manned moon landings were carried out between 1969 and 1972.

Moon Size

• 1/4 width of Earth.

• Radius of 1080 miles.

• Gravity is about 1/6 of Earth.

Earth and Moon to Scale

• If Earth were a basketball, then the moon would be a tennis ball, 23.5 feet away.

• The moon is 238,900 miles away from the Earth.

TidesTides – daily movements of – daily movements of ocean water in regular ocean water in regular patterns.patterns.

Gravitational forces from both the sun and the moon continuously pull on the Earth.

Although the moon is much smaller that the sun, the moon’s gravity is the dominant force behind Earth’s tides.

The Moon produces no light of its The Moon produces no light of its own!own!

The Moon looks bright because it reflects light from the sun.

The Near SideThe Moon rotates in

27.3 days.

The Moon orbits Earth in 27.3 days.

Because the Because the Moon rotates Moon rotates and revolves and revolves at the same at the same rate, we only rate, we only see one side.see one side.

The NEAR side

There is NO DARK SIDE

There is a FAR side….

The rotation period of the Moon with respect to the universe is exactly the same as the rotation period of the Moon around the Earth.

OUT: Why do we always see the same side of the moon?