‘Jesus, there she is!’ cried out a man in Munich as a small black dot bit into the Sun’s perimeter. At around the same time in Newfoundland, a Harvard professor left his tent to witness this ‘exquisite entertainment’ while, perched on a Russian mountain, a French astronomer was rewarded for his lonely vigil by being ‘seized with an universal shivering’. Two and a half centuries later, in 2004, the language was different but the reactions were similar. Equipped with dark glasses and expensive cameras, scientific tourists stationed themselves around the globe to watch the rare astronomical event of the planet Venus passing between the Earth and the Sun.

As Andrea Wulf explains in Chasing Venus, transits of the planet take place in pairs eight years apart; she focuses on those of 1761 and 1769. These double occurrences are separated by over a century, so that although the sequence can never be observed more than once in a lifetime,