Glow-in-the-dark astronauts

The Claim: If the astronauts had actually crossed the Van Allen Belt, the radiation would have killed them

The science: The Van Allen belts are created by Earth’s magnetic field, and protect the planet from dangerous solar radiation. The belts collect this radiation and trap it in a layer surrounding Earth. But unless you deliberately caused your spaceship to hover within this layer for many hours or days, the radiation exposure is well below dangerous levels, like getting an X-ray.