Final answer:
The general length of orbit or orbital period of terrestrial planets varies based on their distance from the Sun, with terrestrial planets like Mercury taking 88 days and Earth taking 365.26 days to orbit the Sun. Giant planets have much longer orbital periods, such as Jupiter's nearly 12 years and Saturn's approximately 30 years due to their greater distances from the Sun.
Step-by-step explanation:
The general length of orbit, or the orbital period of a planetary body is determined by its average distance from the sun, which directly influences the time it takes to complete one full orbit around the sun. For instance, the Earth takes approximately 365.26 days to complete its orbit, with a semi-major axis of about 152 million km and a semi-minor axis of about 147 million km. On this basis, an Earth-to-sun line sweeps out a certain area in one day according to Kepler's second law of planetary motion.
Taking other terrestrial planets into account, Mercury orbits the Sun in approximately 88 days due to its close proximity, covering less area per day compared to Earth. For the giant planets which are farther away, such as Jupiter and Saturn, their orbital periods are significantly longer, with Jupiter taking nearly 12 years and Saturn about 30 years to orbit the Sun. Kepler's third law states that the square of the orbital period is directly proportional to the cube of its average distance from the sun, which explains these variances in orbital period based on distance.
A hypothetical or real planet with an orbital period of 45.66 years would be quite distant from the Sun, reflecting this relationship. For example, Uranus orbits at an average distance of 19 astronomical units (AU) and takes 84 years to complete an orbit, while Neptune, even more distant at 30 AU, requires 165 years. This showcases the vast scale of our solar system and the varying timescales on which different planets orbit our Sun.