The planet with the shortest orbit around the sun is

Analyze the question: It asks which planet has the shortest orbit around the sun. That means the planet that takes the least time to complete one revolution, and which also travels the smallest path because it is closest to the sun.

Concept: The closer a planet is to the sun, the smaller its orbit and the faster it travels. This is Kepler's third law: a planet's orbital period increases with its distance from the sun.

Order of the planets from the sun:

1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune

(Pluto was once counted as the ninth planet, but it is now classed as a dwarf planet.)

Compare the options:

| Planet | Approx. orbital period | |---|---| | Mercury | about 88 days | | Mars | about 687 days (1.9 years) | | Jupiter | about 11.9 years | | Pluto | about 248 years |

Mercury is the closest planet to the sun, so it has the smallest orbit and the shortest orbital period.

Answer: C. Mercury.

Tip: Remember the planet order with "My Very Educated Mother Just Served Us Noodles". The first planet, Mercury, always has the shortest orbit and the fastest revolution. For "longest orbit" questions, pick the farthest planet instead.