According to his calculations, about 20 years of lead time would be sufficient for solar radiation to move the asteroid away from its current course causing it to come nowhere near the Earth.
Mars-bound pioneers will be exposed to radiation levels that could effectively retire astronauts under NASA's current standards, scientists reported Thursday.
Recent studies by researchers at Massachusetts General make the case that the risks of death from a current medical condition often far outweigh the risk of radiation.
"Something like 2% of cancers down the road will come from CT scans now, " says Columbia University radiation biologist Eric Hall, who was not involved in the current study.
More than 70 percent of the centers in the study were using electrocardiographically controlled tube current modulation (ECTCM), which is currently the best-known strategy for reducing radiation dose.
The radiation belt, which contains "two concentric rings of charged particles trapped by Earth's magnetic fields" doesn't affect current astronauts going to and from space because they are moving too fast to be hit by the radiation.