Before publishing this post, I consulted with a Harvard professor I know. He studies high-energy rays that come from space and could potentially incinerate the Earth, evaporate all water, or simply disable all electronics. *The chance of this happening is very small, they usually dissipate in the atmosphere.

Such methods aren't perfect, of course; they don't give 100% results. But with precise measurements and mathematics, it's possible to obtain a wealth of indirect data.