Bodies of the Solar System: Planets, Comets and the Kuiper Belt
The planets, dwarf planets, asteroids and comets that orbit the Sun, the structure of a comet, and where short-period and long-period comets come from at the edge of the Solar System.
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The Solar System family
The Sun is orbited by a whole family of objects. There are the eight planets, but also dwarf planets, and countless smaller bodies: asteroids, meteoroids and comets. This module explores these bodies, the structure of a comet, and where comets come from at the very edge of the Solar System.
Types of body
The main kinds of object in the Solar System:
Planets from the Sun
Put the eight planets in order, starting nearest the Sun and moving outward.
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
Match the body
- Planet
- Dwarf planet
- Asteroid
- Comet
- A large body that has cleared its orbit
- A round body that has not cleared its orbit
- A small rocky body, mostly in the asteroid belt
- A small icy body that grows a tail near the Sun
Between which planets?
Most asteroids orbit the Sun in a belt between which two planets?
- Mars and Jupiter
- Earth and Mars
- Jupiter and Saturn
- Venus and Earth
Gas giants vs rocky planets
The eight planets fall into two groups.
Small Solar System Objects
Select the TWO that count as Small Solar System Objects.
- Asteroids
- Comets
- The planet Earth
- The Sun
The parts of a comet
A comet has three main parts: - The nucleus: a small, solid, icy core. - The coma: a cloud of gas and dust that forms around the nucleus as the comet nears the Sun and its ice turns to gas. - The tails: streams of gas and dust that always point away from the Sun, pushed by the solar wind and sunlight.
Which way does a tail point?
In which direction does a comet's tail always point?
- Away from the Sun
- Towards the Sun
- Always behind the direction of travel
- Always downwards
Where comets come from
Comets come from two distant regions, depending on how long their orbit takes.
The Solar System in words
The eight _____ orbit the Sun, along with dwarf planets and smaller bodies. Rocky asteroids mostly lie in a belt between Mars and _____. A comet is an _____ body whose tail points away from the _____. Short-period comets come from the _____ Belt beyond Neptune.
Spot the comet parts
Tap the TWO features from the list that are parts of a comet.
- Nucleus
- Crust
- Coma
- Equator
- Crater
Name that body
Use the clues to classify each Solar System body.
- A small icy object grows a glowing tail as it approaches the Sun. What is it?
- A small rocky object orbits in the belt between Mars and Jupiter. What is it?
- A round body orbits the Sun but has not cleared its orbit of other objects, like Pluto. What is it?
Describe a comet
Describe the structure of a comet and explain where short-period and long-period comets come from. Write in clear, full sentences.
- Name the three main parts of a comet: the nucleus, the coma and the tails
- Explain which way the tail points, and why
- State where short-period comets come from (the Kuiper Belt)
- State where long-period comets come from (the Oort Cloud)