The 40th anniversary of the Apollo Moon landings this year coincides with the 150th anniversary of the Carrington event, the fiercest solar storm to have ever struck the Earth. So it seems fitting to muse on a link between extreme solar events and the Moon landings. That link is astronaut Harrison Schmitt, who may be the luckiest astronaut alive.

Schmitt is the only scientist to walk on the Moon. He is a geologist and was originally scheduled to fly on the Apollo 18 mission. When Apollo 18 was cancelled, he was shifted up the rota to Apollo 17, kicking out Joe Engle from the team. That was Schmitt’s first piece of luck.

His second was that Apollo 17 did not launch until December. In the August, after the safe return of Apollo 16, a large sunspot appeared on the solar surface and let fly a rash of solar flares that pumped deadly radiation into space. Had Schmitt, or any other astronauts, been in space at the time, they would have perished from a fatal dose of solar radiation.

After Apollo 17 splashed down, solar physicists had some luck too.

The moon rocks Schmitt and his colleagues returned, proved invaluable to solar storm studies. The rocks had soaked up flare particles like sponges during the August outbursts, allowing scientists on Earth a first-hand look at the particles given off by the Sun during these extreme solar events.

This blog was also posted on the BBC Focus website here.