11. Quiz. Choose the correct answer. 1) Which is the brightest planet in the night’s sky? A) Mars B) Saturn C) Venus D) Sun. 2) Which is the oldest planet in our solar system? A) Earth B) Mars C) Jupiter D) Mercury. 3) How many planets are in the Solar System? A) 10 B) 8 C) 7 D) 6. 4) How many moons does Mars have? A) 50 B) 1 C) 13 D) 2. 5) Which of these planets is the smallest? A) Mercury B) Uranus C) Earth D) Jupiter. 6) Which is the closest planet to the Sun? A) Mercury B) Neptune C) Venus D) Earth. 7) Which planet has the most moons? A) Saturn B) Venus C) Uranus D) Mars.