Many Adults Can’t Pass This Elementary School-Level Quiz, Can You?! Jennifer Hillhouse|General Knowledge|9 Mar 2022 Which of these planets is closest to the sun? 74% Retry Correct Incorrect Mercury is closest, at 35.98 million miles from the sun. Next NASA via Getty Images NASA via Getty Images Which of these planets is closest to the sun? Neptune Mercury Earth Jupiter 74% Scroll down to continue on! Next