The mass of the Sun is 2 times 10 to the 30th power kilograms , and the distance between Neptune and the Sun is 30 AU. What is the orbital period of Neptune in Earth years?

Kepler’s third law, when distance is measured in AU and period in Earth years, is P² = a³. For Neptune, a = 30 AU, so P = √(30³) = √27,000 ≈ 164 years. Therefore, the orbital period is 164 Earth years.

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