Which planet takes the longest time to go once around the Sun?
Which planet takes the longest time to go once around the Sun?
(A) Neptune
(B) Mars
(C) Jupiter
(D) Earth
Neptune has the longest orbital period around the Sun among the recognized planets, which takes approximately 165 Earth years (about 60,190 days). As the farthest planet, it has the largest orbit around the Sun and has made only one complete orbit since its discovery in 1846.