What are planets?

What are planets?

By Mike Cummings

​Before we can study and learn about planets, we must first understand what a solar system is!

​A solar system consists of all material that revolves around or is trapped by the gravitational forces of a star. These objects include planets, moons, asteroids, comets, meteors and other space debris.

Multiple Choice

A star and all of the objects that are locked by gravity

around that star is known as;

• a solar storm

• a galaxy

• a solar system

• a solarium

​Our Solar System contains all the matter that surrounds our Sun all the way out to the outer edges of the Oort Cloud. Think of our Solar System being similar to a bubble or balloon with all of the matter trapped inside. The Sun's gravity holds everything together!

Multiple Choice

The large surrounding "bubble" around our star

that is locked by gravity is known as;

• a Solar Balloon

• a Cumulus

  Cloud

• the Oort

  Cloud

• a Solar Bubble

​Planets are large objects that revolve/orbit a star like our Sun. The planets in our solar system are grouped according to their location in relation to the Sun. The Asteroid Belt is the dividing line between the inner planets and the outer planets.

Multiple Choice

What is used as the dividing line between the

inner and outer planets?

• the Oort Cloud

• the Asteroid Belt

• the Kuiper Belt

• a black hole

Multiple Choice

What are considered planets?

• anything that

  revolves/orbits

  a star

• large objects

  revolving/orbiting around planets

• large objects that revolve/orbit

  around a star

​The four planets between the Asteroid Belt and the Sun are the inner planets, these include Mercury, Venus, Earth and Mars. The planets located outside of the asteroid belt are known as the outer planets and they include Jupiter, Saturn, Uranus and Neptune.

Multiple Choice

What can be found located between the Sun and the Asteroid Belt?

• outer planets

• asteroids

• comets

• inner planets

Multiple Choice

Which of the following IS NOT an inner planet?

• Mars

• Ceres

• Earth

• Mercury

• Venus

​There are specific characteristics of the inner planets that differentiate them from the outer planets.

• the inner planets have surfaces made of rock

• inner planets are much smaller in size

• the inner planets have fewer moons

  (only 3 in all)

• the inner planets do not have rings formed around them​

• the inner planets ​are between the Sun and the Asteroid Belt

Multiple Choice

What are the inner planets

primarily made of?

• water

• rock/minerals

• gases//ice

• liquids/gases

Multiple Choice

One of the primary differences between the inner

and outer planets are the number of moons! How many total

moons can be found revolving around the inner planets?

• 3

• 4

• 81

• 67

​Because the inner planets have a

hard rocky surface, they are often

known as the "terrestrial" planets.​

Multiple Choice

Because the inner planets are made of rock

they are considered;

• asteroidal planets

• tertiary planets

• terrestrial planets

• hydrological planets

​The acronym for the inner planets is...."My Very Energetic Mother!"

Remembering this phrase will help you remember the order of the

four inner terrestrial planets.​ You just have to remember that Mercury is the closest to the Sun.

Multiple Choice

In our acronym phrase for the inner planets,

"My Very Energetic Mother," what does "MY" stand for?

• Mars

• Mercury

• Makemake

• Marvelous

​Separating the inner and the outer planets is the Asteroid Belt. This region is thought to be a planet that didn'​t form due to the gravitational forces of Jupiter. This region is made up of large rocky materials rich with minerals. There are several dwarf planets found here, Ceres being the largest.

Multiple Choice

What is it that scientists think about the Asteroid Belt?

• a planet the blew apart

• a planet that

  never formed

• Jupiter's sister

  planet

• Where moons

  are made

Multiple Choice

Which dwarf planet is found in the Asteroid Belt?

• Ceres

• Pluto

• Eris

• Humea

​The outer planets include Jupiter, Saturn, Uranus and Neptune. These planets are located between the Asteroid Belt and the Kuiper Belt. The Kuiper Belt is an icy ring of objects from 30 - 50 AU's away from the Sun. Pluto, the dwarf planet moves in and out of the Kuiper Belt.

Multiple Choice

Which region is found outside the outer planets?

• the Oort

  Belt

• the Asteroid

  Belt

• The Hubble

  Belt

• The Kuiper

  Belt

Multiple Choice

Which planet moves in and out of the Kuiper Belt?

• Eris

• Pluto

• Ceres

• Neptune

​There are specific characteristics that differentiate the outer planets from the inner planets.

• the outer planets are made of gas, liquids and ice

• the outer planets are very large, they

  are known as the gas giants​

• every outer planet has multiple moons, with Jupiter having 79 and Saturn having 82

• ​each outer planet has rings

• ​the outer planets are located between the Asteroid and Kuiper Belt

Multiple Choice

Which outer planet has the most moons?

• Saturn

• Jupiter

• Uranus

• Neptune

Multiple Choice

What are the outer planets primarily made of?

• rock and minerals

• water

• gases and liquids

• hot air

Multiple Select

Choose the outer planets that have rings!

• Jupiter

• Saturn

• Uranus

• Neptune

​The acronym for the outer planets is..."Just Served Us Noodles!"

Remembering this part of the saying will help you ​remember the order of the Outer Gas/Liquid Giants! (Jupiter, Saturn, Uranus and Neptune)

Multiple Choice

Which outer planet is third?

• Uranus

• Neptune

• Jupiter

• Saturn

​Dwarf planets can be found in both the Asteroid Belt and the Kuiper Belt. Dwarf planets are smaller in characteristics than the other planets. Some are smaller than some of the moons surrounding our planets. Ceres was actually discovered first.

Multiple Select

What are the two locations where dwarf planets can be found?

• Oort Belt

• Asteroid Belt

• Kepler Belt

• Kuiper Belt

​Other objects found in our Solar System include comets, asteroids, meteors and moons.

​This diagram shows the location of the Asteroid Belt found between Mars and Jupiter. It also show you the Kuiper Belt which is outside of Neptune and extends out to the Oort Cloud which surrounds our Solar System.

​"My Very Energetic Mother Just Served Us Noodles!"

Multiple Choice

Which is the correct order of the 8 planets from the Sun out!

• Neptune, Uranus,

  Saturn, Jupiter,

  Mercury, Venus,

  Mars, Earth

• Mars, Venus, Earth,

  Mercury, Jupiter,

  Saturn, Uranus, Neptune

• Mars, Earth, Venus, Mercury, Uranus, Jupiter, Saturn, Pluto

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