How do they decipher between orbit, earth rotation and not confuse it with other planets movement?
Earth’s rotation causes all things we can see in the night sky to move from east to west during the course of a single night. From one night to the next, Earth’s orbit around the Sun generally causes objects to rise and set a bit earlier than they did the previous night. The stars are mostly so far away that they essentially provide a “fixed” backdrop against which to measure our own motion as observers on the surface of a rotating and orbiting body and also to note the apparent motion of other objects within our own Solar System (planets, dwarf planets, asteroids, comets, etc). Thus we can account for our own motion and reveal the motion of the other bodies. Some of this took a long time to work out. Kepler produced equations for the orbits of the Earth and Mars, for example, based on observations made by Tycho Brahe over the course of more than 20 years. By selecting observations made either at the same time of Earth’s year (when our planet was essentially in the same position) or th
