Guillaume Le Gentil spent more than 11 years away from his native France just to witness two brief astronomical events. Along the way, he had to survive war, a hurricane, disease, and grumpy officials. When he got home, he’d lost his job and been declared dead. But the real hardship? He missed both events.

Le Gentil was born 300 years ago this week. He studied theology, but decided on astronomy as a career. He became a member of the Royal Academy of Science at age 28.

Le Gentil and other astronomers hoped to measure a 1761 transit of Venus across the Sun from many locations on Earth. The details would reveal the Sun’s distance – the basic “yardstick” for the entire solar system.

Le Gentil planned to watch from India. He headed out in March of 1760. War with England complicated the trip, and his ship was blown off course. On the day of the transit he was still at sea, where it was impossible to make observations.

The next transit was just eight years away, so Le Gentil decided to hang around. He planned to watch from the Philippines. But he got a chilly reception, so he returned to India. He set up an observatory and waited. But the day of the transit was cloudy – until shortly after it was over.

Heartbroken, Le Gentil headed home. It took two hard years to get there – only to encounter even more problems. But he worked things out, and published two volumes about his travels in the name of science.

Script by Damond Benningfield