HOW DOES THE EARTH MOVE?

Try and explain what you see here. Why has this happened Try and explain what you see here. Why has this happened? What is causing this weird circular pattern?

Earth’s Rotation: Earth rotates on its axis once every 24 hours (15o/hr)

Earth rotates in a counterclockwise direction Earth rotates on its axis, at an angle of 23 ½ degrees

Earth’s Revolution Earth revolves around the Sun once every 365 days

Earth’s orbit is described as a slightly eccentric ellipse When (season)is earth closest to the sun? Earth is closer to the Sun in the winter and further away in the summer!

How do planets stay in their orbits? Gravity is a strong attractive force between objects Why is this shape wrong????

The more massive two objects are, the greater the gravitational force between them The closer the two objects are to each other, the greater the gravitational force between them

Therefore.. As planets move closer to the Sun, their orbital velocity (speed) increases

Inertia: Earth does not get pulled into the Sun because of Inertia

An object in motion will continue moving in a straight line at a constant speed unless acted upon by a force – GRAVITY!

Reason for Seasons

1. Tilt of Earth’s Axis Earth’s axis is tilted at 23 ½ degrees During the summer, the northern axis is tilted towards the Sun

During the winter, it is tilted away from the Sun If it were tilted more than this, our seasonal weather would be more extreme (hotter summers and colder winters)

Towards Away Further Closer June 21 Dec. 21

2. Revolution around Sun Earth orbits the Sun in an slightly elliptical shape

Summer Solstice June 21st Earth’s northern axis is tilted towards the Sun Sun has the highest and longest path in the sky in NYS 15 hours of daylight and 9 hours of darkness

Seasons Seasons

23

Winter Solstice 9 hours of daylight and 15 hours of darkness December 21st Earth’s northern axis is tilted away from the Sun Sun has the shortest path in the sky in NYS 9 hours of daylight and 15 hours of darkness

Seasons Seasons

26

Equinoxes March 21st and Sept. 21st 12 hours of daylight and 12 hours of darkness (equal)

The Moon

The Moon The Moon orbits the Earth in ~ 28 days (one month) The Moon also rotates on its axis

Why do we weigh less on the moon?

Moon Phases The moon reflects the suns light Half is always illuminated

As the Moon revolves around the Earth, we see different parts of the illuminated half Because of this, we have moon phases

Moon Phase Animation