COMMENT

by Chris Lintott

When I was a boy, I remember reading that there were two planets known in orbit around Barnard’s Star. This is why Project Daedalus – the British Interplanetary Society’s attempt in the 1970s to think seriously about a design for a starship – chose this star as its proposed target.

The planets were ‘discovered’ by an astronomer called Peter van de Kamp, who looked for tiny changes in the star’s position on the sky. In 1963, he announced that he’d found a regular pattern which was due to a planet orbiting the star every 25 years. By 1969 he was able to announce a second world, this one nearly the size of Jupiter.

Sadly, the observed effects were shown to be caused by tiny changes in the instruments over decades. Still, hearing about these planets reminded me how long astronomers have been planet-hunting – and how lucky we are to watch while such discoveries are really happening.