The Earth and the Moon

I) Formation of the Moon

• A giant Asteroid (the size of Mars) slammed into Earth about 4.5 billion years ago kicking up debris that formed the Moon

II) Moon’s Orbit• How does the moon stay in its orbit around Earth?

A)Gravity – Keeps the Moon from flying off into space

B) Inertia – keeps the Moon going

III) Earth’s Rotation

A) Day & Night1) Earth rotates around its axis2) axis – imaginary line that runs through the North and South Pole3) 1 rotation = 24 hours4) # of daylight hours changes throughout the year because Earth is tilted 23.5 degrees

IV) Earth’s revolution

B) A year on Earth

1) Earth’s revolution around the sun

2) = 365.26 days

3) Leap Year – every 4th year we have to add a day to our year because of the extra 0.26 of a day (Feb. 29)

V) Seasons on earth

A) Due to Earth’s tilt and its revolution around the sun (not the distance from the sun

B) Whichever hemisphere is leaning into the sun is experiencing summer (it receives more direct sunlight)

VI) Earth’s Tides

A)Tides are a result of the Moon’s gravity pulling on Earth’s water

B) The side facing the moon and the opposite side is experiencing high tide

C) Special Tides 1) Spring tides – especially high and especially low tides

- the Sun, Moon, & Earth are in line (New Moon & Full Moon)2) Neap tides – mild high and mild low tides

-when the sun and Moon are at right angles to the Earth (First Quarter & Last Quarter Moons)

VII) Lunar CycleA) It takes 28 days for the Moon to orbit the earth

(a month)

B) The Moon moves 1/28th of its orbit each day so we see it from a different angle each night

VII) Eclipse

A) Solar eclipse – when the moon blocks the light from the sun (occurs only during a New Moon)

VII) Eclipse (cont.)

B) Lunar Eclipse – when the Earth comes between the Sun & Moon, blocking the light that lights up the Moon