Astronauts can be particularly vulnerable to solar storms. The Earth's magnetic field shields us from the worst effects of solar radiation, but when astronauts travel outside of our orbit, they are much more at risk.
So far, astronauts have narrowly escaped the worst of the storms, purely by chance.
Still, some have had very close calls. That is the case for the crew of the Atlantis, who was orbiting the Earth in 1989 when a solar storm hit the Earth. According to the book Storms From The Sun: The Emerging Science of Space Weather, the crew was ordered to shelter in the farthest interior of the shuttle.
Some reported feeling their eyes burning as the radiation hit their retinas, per the Australian Broadcasting Company which reported on the book.
Still, the crew emerged mostly unscathed, and had a rare chance to see beautiful auroras from space, The LA Times reported at the time.
As NASA, SpaceX, and others gear up plans to return to the moon and Mars, though, the risks of solar flares to astronauts will need to be more seriously considered, said Owens.
"If you are trying to send a crew to the moon or Mars, you really need to worry about these things, because that is a serious, potentially fatal radiation dose," Owens said.