ozone layer

"By understanding how much ozone there is and how variable it is, we know more about how the atmosphere changed over time, and even whether Mars once had a protective ozone layer like on Earth."

There are holes in the ozone layer, in our ceilings and in our hearts.

They say that as more and more rockets are launched, the risks of harming the ozone layer increases.

And even craft that burn up completely might cause harm; researchers are concerned that the aerosolized metal could be damaging the ozone layer, reversing years of progress in protecting it.

Along with gaseous reactive nitrogen, satellites burning up as they re-enter the atmosphere at the end of their lives leave tiny particles of aluminum oxide, imperilling the still-recovering ozone layer.