Question: how can I tell which planet has the most moons
Option 0: look through telescope, locate Jupiter. The planet with the most moons in the Solar System is Jupiter, with a total of 63 confirmed moons (as of 2009). Of course, it's always possible that more moons will be discovered orbiting Jupiter in the future, and that number will go up.
Option 1: look through telescope, locate Earth. The planet with the most moons in the Solar System is Jupiter, with a total of 63 confirmed moons (as of 2009). Of course, it's always possible that more moons will be discovered orbiting Jupiter in the future, and that number will go up.
Answer: 0