Space Science Documentary - Searching for ANOTHER Earth - The Planet Hunters Guide

The planets around our star, the sun, are not the only ones out there. For years, people have wondered what exists beyond the one star, eight planets, and 710,000 minor planets (including dwarf planets, asteroids, etc.) in our Solar System. In 600 BC, exoplanets were discussed as we would discuss the idea of alternative universes today – once Aristotle landed on the idea of Earth being unique, that was that and all speculation was shut down. It wasn’t until the Renaissance that the idea was revisited by Giordano Bruno. He claimed that there are ‘countless suns and countless Earths rotating around their suns in exactly the same way’, and that we only see their suns rather than the planets themselves. His teachings led him to be executed for blasphemy and heresy, and his idea was rejected.

In the 20th century, ideas moved more rapidly. Isaac Newton also hypothesised that exoplanets exist, but had no means of testing his hypothesis. In 1952, Otto Struve claimed that we only know of our star and our Solar System but that there is more beyond. In 1992, Wolszczan and Frail found other stars at the end of their lives (pulsars), and three years later Mayor and Queloz observed a Jupiter-sized planet (now termed a “hot Jupiter”) that orbit around their stars. The idea that exoplanets exist had sunk in.