Credit: Pixabay, Ponciano. It’s easy to look at the moon and conclude it’s a lifeless, unchanging sphere. In reality, Earth’s constant companion in the sky is quite dynamic. Since the Apollo missions more than 50 years ago, scientists have known the moon is seismically active. Although it lacks tectonic plates, the moon’s crust is under constant pressure due to its cooling interior and Earth’s gravitational influence, forming faults. These forces also explain why the moon is constantly shrinking...