The Earth and the formation of the Solar System
Our solar system was formed for approx. 4.5 billion years ago. The Sun is the star in the middle, which makes up 99% of the mass of the Solar System, and around it move the eight planets. From the Sun it is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The four innermost planets are small rock planets, while the four outermost ones are large gas planets. But what do we really know about the formation of the Solar System and our Earth? How do we know when the planets were formed and can we explain why they are so different? When did our Earth became habitable, and why do we have our big Moon?
Anja C. Andersen is an astronomer and astrophysicist. Professor at the Niels Bohr Institute of the University of Copenhagen. Her research focuses primarily on cosmic dust and interstellar clouds, and its role in the formation of complex molecules, stars and planets.