“How can one face of a celestial object always face the same side of the object that it is orbiting?”
We all know that objects in space revolve around other objects. The moon revolves around the Earth, the Earth around the sun, and the sun around the center of the galaxy. These objects also usually have their own spin. For example, this spin gives rise to the days and nights on Earth. But what if an object’s rotation was in sync with it’s orbit, so that one side always faced the object it was orbiting? Well, not only is this phenomena possible, but it is also happening in our very own backyard, with our very own moon exhibiting this! When the moon revolves around the Earth, the gravity from our planet will cause the moon’s shape to be slightly from solid tides making the moon distorted to give it an almost (American) football shape to it. This distortion means that there will alway be a portion of the moon closer to the Earth then the rest, which results in that side experiencing a greater force being “hooked” to the Earth, causing it to stay on one side. Astronomers and Astrophysicists have termed this phenomena tidal locking as a result of the solid-tide induced locking on the moon.