The magnetic storm watches continue through Monday the 9th, with active to minor storm conditions expected. Moderate quakes continued in a wide range of regions, especially along the western coast of Central America and southwest Asia. A small but very shallow quake was reported near Helena Montana and was felt as a loud rumbling by local residents. Earth's atmosphere and magnetosphere allow adequate protection for us on the ground, but astronauts in space are subject to potentially lethal dosages of radiation. The penetration of high-energy particles into living cells, measured as radiation dose, leads to chromosome damage and, potentially, cancer.
Large doses can be fatal immediately.
In October 1989, the Sun produced enough energetic particles that an astronaut on the Moon, wearing only a space suit and caught out in the brunt of the storm, would probably have died.