ABSTRACT
Ozone is a Jekyll and Hyde molecule. Although it is dangerous at ground level, at high altitudes it protects people from the battering the Earth gets from radiation in space. The ozone absorbs a lot of the ionising radiation, preventing it from reaching the ground and damaging both people and the rest of the natural world. Ozone is a form of oxygen where there are three atoms in the molecule rather than the usual two. It's written O3 and is a pale blue gas with a smell rather like bleach. Ozone is mostly found above 10 km in the stratosphere where it is formed by the action of ultraviolet (UV) radiation on oxygen. An ozone layer was first suggested in the 1930s, but it took 20 years for research to show that this ozone might be destroyed if it came into contact with the wrong sort of chemical.
