Step 3 of 18 · Observing the universe · SC4-OTU-01
The solar system
Eight planets, one star, and distances so big we measure them in light.
Learn it
Describe the Sun, the planets and their features, and the scale of space
Idea 1 of 4
One star, eight planets
The Sun is a star — a huge ball of hot gas that makes its own light. Eight planets orbit it: Mercury, Venus, Earth and Mars are small and rocky; Jupiter, Saturn, Uranus and Neptune are giants made mostly of gas and ice.
Know it by heart
Say each one in your head, then tap to check.
Try it
Play — nothing here is marked
Evenly spaced so you can see them all — switch to true distances to see how much that lies.
A full-marks answer
Explain why Venus is hotter than Mercury, even though Mercury is closer to the Sun.
2 marksBuilt one line at a time — say the next line before you reveal it
- Venus has a very thick atmosphere of carbon dioxide.(name the feature)
Words to know
Tap a card to flip it
Step 3 · last bit
Ready? Prove it.
A round of ten. Score 8 or more and this step is done — then on to day, night and seasons.