By Miles Hatfield NASA's Goddard Space Flight Center About 50 miles up, Earth's atmosphere undergoes a fundamental change. It starts at the atomic level, affecting only one out of every million atoms (but with about 91 billion crammed in a pinhead-sized pocket of air, that's plenty). At that height, unfiltered sunlight begins cleaving atoms into …
What Is a TID? It’s a TAD More Complicated Than We Thought
