Fun Facts About the Planets

It's fun to know facts about the planets that share the solar system with Earth. Our solar system is made up of eight planets, one dwarf planet, comets, meteors, moons, the sun and an asteroid belt. The planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. 

Here are some fun things to know about our solar system and its planets:

• Jupiter is the biggest planet. 
• Mercury is the smallest planet and the closest to the sun. Because it is so close to the sun, daytime temperatures on Mercury can reach 800 degrees Fahrenheit.
• A year is the amount of time it takes a planet to orbit the sun. Earth's orbit takes just over 365 days. A year on Mercury lasts only 88 days. Neptune's years last more than 60,000 days.
• Neptune has not completed an orbit since it was discovered in 1846. It will complete its first orbit since its discovery on July 12, 2011.
• Earth is the fourth largest planet, after Jupiter, Neptune and Saturn.
• There are "inner" planets and "outer" planets. The inner planets are Mercury, Venus, Earth and Mars. The outer planets are Jupiter, Saturn, Uranus and Neptune.
• The inner planets are made mostly from rock and have no moons or just a few moons. Earth has one moon.
• The outer planets are made from mostly gas, are ringed and have many moons.
• Earth is the densest planet. Saturn is the least dense. 
• Venus is the brightest planet.
• Mars has the biggest volcano in solar system, Olympus Mons, which stands 27 kilometers high. Its crater is 81 kilometers wide.
• Saturn is the lightest planet. It would float in water.
• Jupiter is so big, you could fit 1,300 Earths inside of it.
• Jupiter has the biggest moon in our solar system. The moon is called Ganymede. It is bigger than Mercury and Pluto.
• Until 2006, Pluto was considered a planet. In that year, the International Astronomical Union set new rules for defining a planet, and Pluto was reclassified as a dwarf planet, or plutoid.
• Pluto is made from mostly rock. It has one large moon and two smaller moons.
• Sometimes, Pluto's orbit is closer to the sun than Neptune's. This means that the order of the planets change, making Neptune last. The last time Neptune was last in the order of planets was from September 5, 1989, through February 1999.