The Planet Quiz

Jupiter is about 143,000 km across, more than 11 times the width of Earth.

Venus's thick carbon dioxide atmosphere traps heat, keeping the surface around 467 C, even hotter than Mercury.

Venus takes about 243 Earth days to spin once but only about 225 days to circle the Sun.

Saturn's average density is about 0.69 grams per cubic centimetre, lower than water's 1.0.

Uranus is tilted about 98 degrees, so it rolls around the Sun like a ball.

Phobos and Deimos are named after the horses that pulled the chariot of Ares, the Greek god of war.

NASA explains that iron minerals in the Martian dirt oxidize, or rust, giving the planet its color.

Mercury's average distance from the Sun is about 58 million km, the shortest of any planet.

The International Astronomical Union made the change in 2006. New Horizons flew past Pluto later, in 2015.

NASA says the Sun holds about 99.8 percent of all the mass in the solar system.

A day on Jupiter lasts about 9.9 hours, the shortest of any planet.

Charon is about half the size of Pluto, the largest moon compared with its parent world in the solar system.