Earlier quoted context omitted.
It does have plenty of atmosphere, so radiation isn't a problem. (The problem is everything else, as usually is the case on space.)
Venus has plenty of atmosphere above the surface, but not above the point where there is 1 ATM of pressure. In case of Earth most of protection comes from our magnetic field. The reason is that magnetic field sweeps ALL charged particles coming from the sun while atmosphere only stops some. When a particle drops into atmosphere it has a chance to collide with an air molecule, the deeper the higher the chance. But the…
I’ve seen many books etc suggest the earths magnetic field is required, but I haven’t found direct evidence for it doing anything beyond protecting the ozone layer.