Planets of the Solar System Quiz: Name All 8 Planets in Order

This quiz asks for the eight planets of the solar system. The board shows the Sun and eight empty orbits, in the real order from the Sun outward.

You can name the planets in any order you like. Each planet moves to its own place in the row, so if you type Neptune first, Neptune appears in the eighth orbit and the seven orbits before it stay empty.

The size of each empty orbit is the size of the planet that belongs in it. The ring for Jupiter is the widest one on the board, and the ring for Mercury is the smallest.

How to play

• Type the name of any planet. You do not have to press Enter — the quiz accepts the name as soon as you spell it.
• A correct name fills its orbit with the planet and prints the name under it.
• Press Enter on a name the quiz does not know to clear the box.
• The clock starts on your first keystroke, so you can look at the board first.
• Select Give up to end the run and see the planets you missed.
• Your score is the number of planets you name. The maximum score is 8.

What counts in this quiz

• The eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
• The spelling of each name, in English. Earth also accepts "the Earth" and the Latin name Terra.
• Capital letters do not matter. "mars" and "Mars" both count.
• The leaderboard ranks a full board of 8 by time, because almost every player reaches 8. The fastest full board wins.

What's not included — and why

• Pluto is not one of the eight. The International Astronomical Union moved it to the dwarf planets in 2006. Type it and the quiz will tell you so.
• The other dwarf planets — Ceres, Eris, Haumea, Makemake — are not in the quiz either.
• Moons are not in the quiz. Earth's Moon, Titan and Europa all orbit a planet, not the Sun.
• The Sun is not a planet. It is the star at the centre, and the board draws it for you.

Good to know

• The order from the Sun is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Many people learn it with a sentence such as "My Very Easy Method Just Speeds Up Naming Planets".
• Jupiter holds more mass than all the other seven planets put together.
• Venus is hotter than Mercury, although Mercury is closer to the Sun. The thick clouds of Venus trap the heat.
• Neptune was found with mathematics. Astronomers predicted its position from the orbit of Uranus, then pointed a telescope at that spot in 1846 and saw it.
• A year on Neptune lasts about 165 Earth years. It has completed one orbit since it was discovered.