The Eight Planets: Concept Map

Concept Map

Organise the vocabulary, quantities and relationships into a connected model.

This extension applies that lens specifically to The Eight Planets.

Eight planets travel around the Sun. In order of distance, starting closest:

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

They fall into two clear groups:

A few facts worth carrying:

• Mercury is the closest to the Sun and the smallest planet.
• Venus is the hottest, because a thick blanket of gas traps the heat — hotter even than Mercury.
• Mars looks red because its dust is rich in iron, which has rusted.
• Jupiter is by far the largest planet: all the others would fit inside it.
• Saturn has the brightest ring system, made of countless pieces of ice and rock.
• Neptune is the furthest planet from the Sun.

Worked example — where does Pluto fit in?

Pluto used to be called the ninth planet. Astronomers later agreed on a stricter definition of "planet", and Pluto did not meet all of it — it is small and shares its region of space with many similar icy objects. It was reclassified as a dwarf planet in 2006.

Notice what happened: nothing about Pluto changed. The definition changed. That is science working properly — when better evidence arrives, scientists rewrite the rule rather than defend the old one.