Planets are constantly floating around us, but during ideal (weather)conditions on planet earth, we can only see those other planets as small dots in the sky. If this was the only way to study the planets, we would probably not be very knowledgeable about them. Luckily, we have satellites and rockets, and we build planetariums. A mini solar system right here on earth. Even Archimedes is likely to have used one of them. Astronomical clocks have been around for a long time.