Transcript Orbits of Planets and Moons

Orbits of Planets and
Moons
Orbits
Universal Law of
Gravitation
9J Gravity and space
Orbits
9J Gravity and space
Orbits
1. All of the planets in our solar
system revolve around the
sun.
2. The moon revolves around the
Earth.
3. Two forces keep the planets in
orbit:
a. Inertia – Keeps the planet in a
path moving away from the sun
b. Gravity keeps the planet moving
towards the sun.
c. A balance of these 2 forces keep
the planet moving towards the
sun.
9J Keeping your feet on the ground
Wherever you are on Earth,
the same force keeps your
feet on the ground.
It holds our atmosphere
around us and keeps the
oceans on the Earth.
What is it?
You remember – it’s...
9J Keeping your feet on the ground
Universal Law of Gravitation
All Objects in the universe are attracted to all other objects
1. The size of the planet and
its speed determines the size
of the planet’s orbit.
2. Planets closer to
the sun have smaller,
faster orbital paths.
3. Planets farther
away from the sun
have longer, slower
orbital paths.
9J Working outwards from the Sun
Label the planets in order, starting with Mercury nearest the Sun.
Earth
Mercury
Jupiter
Saturn
Neptune
Uranus
Mars
Sun
Venus
Distances not to scale
9J Satellite links
So theWhat’s
Moon is
a a
satellite
of the Earth.
satellite?
There are also pieces of broken
Anything
spaceship and other debris in
that’s in orbit
orbit, that have been trapped by
around aput artificial
Scientists
the Earth’s gravitational field.
larger body.
satellites
in orbit round
the Earth too.
9J Quiz
How much do you know about our Universe?
1. The Moon orbits the Earth in…
a) a circle
b) an ellipse
c) a spaceship.
Correct
Answer: B
2. Jupiter’s gravitational pull is…
a) larger than Earth’s
b) smaller than Earth’s
c) the same as Earth’s.
Correct Answer: A
(It is about 2.5 times
that of Earth’s
Gravity)
9J Quiz
3. The Sun is at the centre of the…
a) Earth
b) Universe
c) Solar System
Correct
Answer: C
4. The stars and planets stay in their places because of…
a) glue
b) gravity
c) speed.
Correct
Answer: B
9J Space words
Match each word to its correct meaning.
gravity
solar
orbit
lunar
ellipse
satellite
word
meaning
orbit
the path a satellite takes around a body
ellipse
a ‘flattened circle’ shape
gravity
force that pulls two bodies towards each other
satellite
Anything in orbit around a larger body
lunar
to do with the Moon
solar
to do with the Sun
9J Let’s stay together
Why do planets orbit the Sun? It’s the result of gravity.
What will happen if you switch the gravity off?
Explain how gravity keeps the planet orbiting the Sun.