Earth, Moon, Sun

Describe Earth's Axis

Earth's rotation axis is tilted. The tilt of the Earth's rotation axis is always in the same direction by the same amount.. During half of Earth's orbit, the north end of the rotation axis is toward the sun. During the other half of Earth's orbit, the north end od the rotation axis is away from the sun.

How much of the Earth is in daylight at any given time?

Half

Solstice

a day when Earth's rotation axis is the most toward or away from the Sun. Two days each year when the sun is overhead at either 23.5 deg north or south. Each of these days is known as a solstice

Which direction does the Earth rotate?

from West to East or counterclockwise

day

the time required for Earth to rotate once on its axis. The Earth takes 365.24 days to orbit the Sun

year

the time required for the Earth to orbit once around the sun, 365.24 days

Spring & Summer in the Northern Hemisphere

During one half of Earth's orbit, the north end of the rotation axis is toward the Sun. Then, The Northern Hemisphere receives more energy from the Sun than the Southern Hemisphere. Temperatures increase in the northern hemisphere and decrease in in the southern hemisphere. Daylight hours last longer in the northern hemisphere, and night lasts longer in the southern hemisphere. This is when spring and summer happen in the northern hemisphere, and fall and winter happen in the southern hemisphere.

Does the North pole ever directly point at the Sun?

No because the tilt of the Earth's axis is 23 1/2 degrees

Revolution

The movement of one object around another object. Earth completes one revolution around the sun once every year.

The Earth-Sun System

The nearest star to the Earth is the Sun. The Earth moves around the Sun in a circular path.. The Earth makes one complete revolution around the Sun every 365.24 days. The Earth orbits the Sun because of the Sun's gravitational pull. As Earth revolves around the Sun, it spins. The spinning motion is called a rotation. The Earth rotates on a rotation axis.. The Sun looks like it is moving across the sky from east to west when the Earth is actually moving around the Sun from west to east.

orbit

The path an object follows as it moves around another object. Earth's orbit is a slightly flattened circle.

Rotation

The spinning of Earth on its axis. Earth's rotation on its axis causes day and night. It takes Earth about 24 hours to rotate once on its axis.

Why do we have changing seasons?

We have seasons because of 1)the tilt of the Earth's rotation axis, 2) combined with Earth's motion or revolution around the Sun, that causes the seasons to change

leap year

Year that has an extra day; occurs every fourth year

Equinox

a day when Earth's rotation axis is leaning along Earth's orbit, neither toward nor away from the Sun Means "equal night". The length of daytime and nighttime are the same

How many degrees does the Earth rotate per hour?

15 degrees

How many major time zones is the Earth divided into?

24

Axis

An imaginary line that passes through Earth's center and the North and South poles, about which Earth rotates

Fall and winter in the northern hemisphere

During the other half of Earth's orbit, the north end of the rotation axis is away from the Sun. Then, the northern hemisphere receives less solar energy than the southern hemisphere. Temperatures decrease in the northern hemisphere and increase in the southern hemisphere. This is when fall and winter happen in the Northern hemisphere, and spring and summer happen in the southern hemisphere.

What happens when the north pole tilts towards the Sun?

It is summer in countries in the Northern Hemisphere. It is winter in countries in the Southern hemisphere

What happens when the north pole tilts away from the Sun?

It is winter time in the Northern Hemisphere. It is summer time in countries in the Southern Hemisphere.

How long does it take the Earth to make one complete rotation?

It take 1 year or 365.24 days for the Earth to roate around the Sun.

Spring Equinox or vernal equinox

Occurs around March 21st and marks the beginning of spring in the Northern Hemisphere. The Earth continues on its path, and our north pole starts moving towards the Sun again. The Sun moves upwards in our skies and the days continue getting longer. Again, as we reach a midpoint when day and night are both 12 hours long. This is called the "vernal or spring equinox" and happens around March 21st.

Autumn equinox

Occurs around September 23rd and marks the beginning of fall in the Northern Hemisphere. The north pole begins to move away from the Sun. The sun rises lower in the sky so the days start getting shorter. When the Sun is at its mid-point in the sky, we reach the autumn equinox, around September 22nd. Day and night are both 12 hours long and its the beginning of autumn.

Explain the process of Day/night

Our days and nights are caused by the spinning of the Earth. Earth rotates on its rotation axis in a counterclockwise direction, from west to east. One complete rotation of the Earth takes about 24 hours or 1 day. This rotation helps produce Earth's cycle of day and night. It is daytime on the half of the Earth facing toward the Sun and nighttime on the half of the Earth facing away from the Sun.

What area of the Earth receive the least concentrated amounts of Sun radiation?

The North and South Pole

What area of the Earth receives the most concentrated amount of Sun radiation?

the equator