What two factors keep planets orbiting around a star like the sun?

1
What two factors keep planets orbiting around a
star like the sun?

• Inertia- The tendency of
• an object to continue in a
• straight line or an object
• at rest to stay at rest
• Gravity- The force that pulls objects toward each
  other

2
Planet- one of the 8 celestial bodies revolving
around the sun.
Planet requirements- 1. Revolve around sun 2.be
spherical 3.clear orbital path.
3
We ___________ around the sun.
revolve
When we orbit or revolve around the sun, we do
not travel in a perfect circle. We revolve
around the sun in an elliptical path. An ellipse
is kind of like a squashed circle.
4
Pluto is a considered a dwarf planet. It lost
its planet status because it had NOT cleared
its orbital neighborhood.
5
What are the planets of our solar system?

• Mercury
• Venus
• Earth
• Mars
• Jupiter
• Saturn
• Uranus
• Neptune

6
How can we remember the order of these 8 planets?

• By remembering this sentence My very eager
  mother just served us nachos!

7
Since there are two planets in The Solar System
that start with M, Mercury and Mars, how can we
remember which is first?
M V EM JSUN
My Mercury
Mother Mars
8
Name the inner planets? Name the outer
planets? How are they different?
Mercury, Venus, Earth, Mars
Jupiter, Saturn, Uranus, Neptune
Inner planets a terrestrial or rocky. Outer
planets are gaseous.
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10
What do we say to remember our planets?
My
Very
Eager
Mother
Just
Served
Us
Nachos!
Mars
Jupiter
Earth
Mercury
Venus
Neptune
Saturn
Uranus
11
An asteroid belt separates the inner and outer
planets.