All of the eight Planets in the Solar System formed approximately 4.6 billion years ago. They all have more or less the same age. And even though they don’t look the same, they were made out of the same cloud of material. This is called a “protoplanetary disc” and it is like a pancake of dust and gas that is leftover after a star – in this case, the Sun – forms. So here’s an interesting question.

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