EVER since the Apollo 11 flight to the Moon in 1969, astronauts have reported seeing weird spots, streaks and clouds of light. Now we know the cause.
Scientists had already worked out that the most likely cause was high-energy particles from space, known as cosmic rays, hitting the astronauts’ eye. But they didn’t know which particles were involved, how they cause the flashes, and whether there is any risk to health.
So between 1995 and 1999, 10 astronauts on the Russian space station Mir took part in tests to try to work out what was happening. They wore a helmet…
