Final Answer:
c. A planet’s mass does not affect orbital period.
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Explanation:
Orbital period (how long a planet takes to go around the Sun) depends mainly on its distance from the Sun — not its mass. This is described by Kepler’s Third Law: the square of the orbital period is proportional to the cube of the average distance from the Sun.
Look at the table:
- Mercury is very light (0.06 Earth masses) and close (0.38 AU) → short year (88 days).
- Venus is heavier (0.82 Earth masses) but farther (0.72 AU) → longer year (225 days).
- Earth is 1 Earth mass at 1 AU → 365 days.
- Mars is lighter than Earth (0.11 Earth masses) but farther (1.52 AU) → longer year (687 days).
- Jupiter is huge (318 Earth masses) and very far (5.20 AU) → very long year (about 12 Earth years).
Notice: Mars has much less mass than Earth, but a longer orbital period because it’s farther out. Jupiter has huge mass, but its long year is due to its great distance — not its mass.
So mass alone doesn’t determine orbital period; distance does. That’s why statement
c is correct.
Parent Tip: Review the logic above to help your child master the concept of kepler s third law worksheet.
