 In this video, we will begin to look at some of the key features that describe the parts of our solar system. Quite simply, it's the name given to the collection of planets and other bodies that orbit a star. It's only recently, by using satellites such as Kepler, that we now know that our own solar system is not unique and indeed they may be common around many other stars. Our solar system consists of a central star, our sun, and eight orbiting planets. Remembering their names in the right order can be tricky, so often we use a silly verse to help. One example is my very easy method, a just sun. Mercury, Venus, Earth, Mars, asteroids, Jupiter, Saturn, Uranus, and Neptune. Let's begin by looking at the inner planets, from the sun to the asteroid belt. There is a lot to take in, so you may want to pause the video to have a good read. Did you notice which was the warmest planet? Go back and check if you were right. More on that at the end of this video. Beyond the orbit of Mars, there is the asteroid belt. This is about 150 million kilometers wide and consists of irregular bodies that orbit the sun which are made from rock and ice varying in size from dust grains up to one so large, 945 kilometers across. It has a name, Ceres. It is thought that the asteroid belt is part of a planet that failed to form because of its gravitational influence of nearby Jupiter. The warmest planet, if you checked, is Venus and not Mercury. Although it's much further away from the sun than Mercury, it has an atmosphere very rich in carbon dioxide which has resulted in a very effective greenhouse effect. Few probes sent to the surface of Venus have survived for more than a few hours in the hot and corrosive atmosphere. The Earth exists in what we call the Goldilocks zone. We are neither too near the sun nor too far away to prevent water being a liquid. We believe liquid water is essential for life to begin and so far we haven't found life anywhere else in our solar system though the water trapped beneath the surface of the moons of Saturn or Jupiter may yet yield simple examples. Although we have now discovered many distant solar systems very few have planets in their equivalent Goldilocks zone so we are unsure if life may be common, rare or non-existent around other stars.