The Earth, The Moon & The Sun

THE SUN

The Sun

• The sun is a star; basically a giant ball of

burning hydrogen

– Giving off heat and light!

• It is the star that all the planets in our solar

system revolve around

The Sun

• Why is the sun’s light important for life

on Earth?

– Warms up the Earth

• The Earth absorbs the light and its heat

– Illuminates the Earth

• Light reflects off of the ground and objects to our

eyes

– This is how we see!

• Light reflects off the moon at night

Day and Night

• What causes the change from day to

night?

Rotation of the Earth

• The Earth rotates on a tilted axis

• How long does it take to make one

turn?

– 24 hours!

Rotation of the Earth

• At any given moment part of the Earth is

facing the sun and the other part is

facing away from the sun

– Facing the sun = daytime

– Facing away from the sun = nighttime

The Seasons

• What causes the seasons?

The Seasons

• What causes the seasons?

– The revolves around the Sun

– It takes 365.25 days (one year) for the Earth

to make one revolution around the sun.

The Seasons

– Remember that the Earth is on a tilt

• So at any point in time part of the

Earth is tilted towards the sun and

part of it is tilted away

–Tilted towards the sun = Summer

–Tilted away from the sun = Winter

The Seasons

• The tilt is very important for the amount of

solar rays hitting the Earth, which relates

to the heat given to those areas

oRays hitting the Earth straight on → The

Equator

oRays hitting the Earth on an angle→ The

Northern and Southern Hemisphere

The Seasons

• The combination of the tilt and how the

rays are hitting the Earth determine the

temperature and climate of the Earth

at any given time

THE MOON

The Moon

• A moon, or natural satellite, is a celestial

body (a thing that is in space) that orbits

around another celestial body that is not

a star

The Moon

• Why can we see the moon?

– The moon does not give off any light itself, it

simply reflects the light from the Sun

The Moon

• Ever heard of the dark side of the

moon?

– The Earth actually only ever sees one side of

the moon because it takes the same amount

of time to rotate on itself as it does to make

one turn around the Earth

– We call the side that the Earth cannot see the

dark side of the moon

Phases of the Moon

• The moon doesn’t always look the same:

sometimes it looks completely round,

and yet sometimes all we see is a small

crescent

Phases of the Moon

• Have you ever noticed that sometimes

there is no moon at all?

– This is called the new moon

– This happens when the moon is between the

sun and the Earth so that the illuminated

side is away from the Earth

Phases of the Moon

• Eventually, more and more of the moon

becomes illuminated, and then less and

less until there is another new moon

– This happens about every 29.5 days

What’s going on here?

Homework

• Complete the crossword puzzle!