Earthquake sensors can detect sonic booms generated by reentering space debris to help track the potentially dangerous objects in near real time.
We live near a fusion reactor in space that provides all our heat and light. That reactor is also responsible for the creation of various elements heavier than hydrogen, and that's true of all stars. So, how do we know that stars are element generators? Many clues lie hidden in stellar spectra, since they contain fingerprints of various elements cooked up by the stars.

