Less than a month ago, I attended a public lecture in which the president of the International Astronomical Union (IAU), Dr Robert Williams, reported that astronomers around the world had found over four hundred planets outside our own Solar System. He joked that these exoplanets were being discovered so rapidly that he might have to update his presentation to four hundred and fifty planets by the time his tour ended.
He must be laughing pretty hard now – less than a month later the official count has already hit five hundred! In fact, according to the Extrasolar Planets Encyclopaedia, the count at the time of writing this article is five hundred and four! Think about that for a minute. Five hundred and four other worlds orbiting stars near our own, and more found almost every day! For a bit of historical perspective on just what this means, watch the video attached left.