A few quick and simple facts for each planet...
- The smallest planet in the Solar System and the closest to the Sun.
- Mercury experiences the greatest temperature variation in the Solar System. Because it's so close to the Sun, Mercury gets very hot during the day (427°C). However, because it has no atmosphere to hold heat, it gets very cold at night (−173°C).
- The surface is covered with craters and looks a lot like Earth's Moon. This indicates that there has been no geological activity for billions of years.
- More facts about Mercury
- The second planet from the Sun is the hottest, due to the greenhouse effect caused by a thick layer of clouds made from sulphuric acid.
- The atmosphere is almost 100 times as thick as Earth's, with pressure strong enough to crush a human.
- From Earth, Venus is one of the brightest objects in the night sky. It gets bright enough to cast shadows.
- More facts about Venus
- The only place we know of that has life.
- The only place we know of that has liquid water on the surface.
- Has one moon which is unusually large compared to the planet it orbits.
- More facts about Earth, Facts about the Moon
- About 1/3 the size of Earth, Mars is the second-smallest planet in the Solar System.
- Despite its red appearance, Mars is cold. The temperature can get as high as a nice day on Earth (30°C) but most of the time it's well below 0°C (down to -175°C at the poles).
- People have never been to Mars but we have sent lots of robots there to learn about it. Mars is the only planet apart from Earth that people might be able to travel to and live on in the foreseeable future.
- More facts about Mars
- Jupiter is the largest planet in the Solar System, containing more mass than all the other planets combined.
- It is the first of the gas giants, with no solid surface. If you tried to land on Jupiter you'd just sink into the planet.
- The most famous feature is the Great Red Spot, a storm bigger than the planet Earth that has been raging for hundreds of years.
- More facts about Jupiter
- Saturn's rings are made mostly of billions of chunks of ice, ranging from microscopic to several metres in size.
- Its biggest moon, Titan, is the only known moon to have an atmosphere and liquid on the surface (liquid methane).
- Saturn has such low density that it would float in water (if you could find a big enough body of water and keep the planet from dissolving).
- More facts about Saturn
- Along with Neptune, Uranus is classified as an ice giant because it contains more ices than the gas giants Jupiter and Saturn. Otherwise all the giant planets are fairly similar.
- Uranus is the only planet in the Solar System to rotate "on its side". Other planets have their axis of rotation perpendicular to the plane of the solar system (so they rotate "upright" like a spinning top) but Uranus' axis is parallel (so it rotates "facing forward" like a windmill).
- More facts about Uranus
- The outermost major planet has a blue appearance, caused by traces of methane in the planet's atmosphere.
- Neptune has giant storms known as dark spots, similar to Jupiter's Red Spot.
- It was the first planet to be discovered using mathematics, after scientists realized that something was causing the orbit of Uranus to change slightly.
- More facts about Neptune
- Gas giant planets (like Jupiter, Saturn, Uranus and Neptune) don't have a solid surface. If you tried to land, you'd just sink into the planet and get stuck.