Earth in Space, Gravity and Motion, 13-1

Rotation

The spinning of a body such as a planet, on its axis is called _

Orbit

The path that a body follows as it travels around another body in space is called an _

Revolution

A complete trip along an orbit is called

Revolution

Keeps moons, planets, stars, in their own orbit

365.25

It takes _ days for Earth to revolve once around the sun, this is one year for Earth

24

It takes Earth ____ hours to rotate once on its axis; this is one day on Earth

Causes day and night

Rotation is a direct cause of …….

Seasons

Are mainly caused by the 23.5 tilt of the Earth's axis and the revolution around the sun

Away

During our winter the Northern Hemisphere is tilted _ from the sun

Toward

During our summer the Northern Hemisphere is tilted ____ the sun

Equinox

The 2 days when the whole planet has equal day and night (March 21 and September 21)

Solstice

The longest and shortest days of the year; December 21 and June 21

June 21

The north pole has sun all day; the north has the longest day, the southern hemisphere has the shortest day.

Dec 21

The south pole has sun all day; the south has the longest day, the northern hemisphere has the shortest day.

March 21 and September 21

The equinoxes

High angle of the sun

Happens in the summer, we get a lot of energy from the sun

Low angle of the sun

Happens in winter, we get low energy from the sun.

Force that keeps planets and moons on their orbit

gravity of the larger body

Newtons 1st law

object in motion stays in motion, object at rest stays at rest unless acting upon by an outside force

two factors working together to keep Earth revolving around the sun

gravity and inertia

what keeps moon close to Earth

gravity between earth and moon

what keeps Earth close to sun

gravity between earth and sun