Here's why:
* Mass: The Sun is significantly more massive than Jupiter. Gravity is stronger between objects with larger masses.
* Center of Mass: The center of mass of the Sun-Jupiter system is actually *inside* the Sun, but not at its very center. This means Jupiter actually orbits around a point within the Sun.
* Newton's Laws: Newton's laws of motion tell us that for equal forces, the object with less mass will experience a larger acceleration. Therefore, Jupiter, being less massive, will move more than the Sun.
It's important to note that both objects are actually moving, just at different scales. The Sun "wobbles" slightly due to Jupiter's gravitational pull, but this wobble is very small compared to Jupiter's orbit around the Sun.
