A Tour Through Our Solar System Quiz

Answer:

The eight planets of the solar system are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. They orbit the system's star, the Sun.

The four terrestrial planets are so named because of their density and the materials they are composed of.

Mercury, apart from being the planet closest to the sun, is also the fastest one to rotate around the star.

Venus is hot because of the huge concentration of greenhouse gases in its atmosphere. Venus takes longer to rotate around its own axis, requiring 243 Earth days to do so. Yet, being closer to the Sun than Earth, a full rotation around the star requires only 225 Earth days, so a Venus day lasts longer than a Venus year.

Mars is known as "the Red Planet", because it appears red, which has to do with the huge concentration of iron oxide in its surface. Its two satellites are named for the sons of Ares, who is the ancient Greek god of war, analogous to the Roman Mars.

The Moon is Earth's natural satellite, meaning it orbits around Earth. A full lunar rotation around the Earth is roughly an Earth month (after all, the word "month" derives from the word "moon").

From Jupiter to Neptune, the planets are gaseous in composition, with much lower density than the terrestrial ones. Jupiter is so named by the Roman name for the god of thunder. Galileo Galilei was the first astronomer to discover that Jupiter has its own satellites, including Europa, Io, Ganymede and Callisto.

Saturn, named for the god of time, is the remotest planet that can be seen without a telescope. Its rings, however, can't be seen with a naked eye. Among Saturn's satellites is Titan, one of the biggest satellites in the solar system.

Uranus was discovered in 1781 by English royal astronomer William Herschel. Herschel had created his telescope manually, all by himself and at first he thought he'd discovered a star. But, after looking more closely, he saw that it was a planet, since it orbited the Sun.

The discovery of Neptune has been a matter of controversy since it occurred in 1846. Established scholarly convention has it, however, that the planet was discovered by the English astronomer Adams and the French astronomer Le Verrier independently of each other, yet simultaneously. There is a considerable number of astronomers disputing it, however, pointing out that a number of earlier observations were made, but without recognising the significance of what was being seen.

Once there was a ninth planet, Pluto, but in 2006 he was demoted to a dwarf planet.