Latest MCQs on Universe for Competitive Exams

21. Which planet has the shortest day in the solar system?
A) Jupiter
B) Saturn
C) Mars
D) Earth
Correct Answer: A) Jupiter
Explanation: Jupiter completes one rotation in about 10 hours.

22. Which planet is the farthest from the Sun in our solar system?
A) Uranus
B) Neptune
C) Pluto
D) Saturn
Correct Answer: B) Neptune
Explanation: Neptune is the most distant planet since Pluto’s reclassification.

23. What is the name of the galaxy expected to collide with the Milky Way in about 4 billion years?
A) Triangulum
B) Andromeda
C) Whirlpool
D) Sombrero
Correct Answer: B) Andromeda
Explanation: The Andromeda Galaxy is on a collision course with the Milky Way.

24. Which planet has the longest year in the solar system?
A) Neptune
B) Uranus
C) Saturn
D) Jupiter
Correct Answer: A) Neptune
Explanation: Neptune takes about 165 Earth years to orbit the Sun.

25. What is the name of the first human to travel into space?
A) Neil Armstrong
B) Yuri Gagarin
C) Buzz Aldrin
D) Alan Shepard
Correct Answer: B) Yuri Gagarin
Explanation: Yuri Gagarin orbited Earth in 1961.

26. Which planet is known for its blue color due to methane in its atmosphere?
A) Uranus
B) Neptune
C) Saturn
D) Jupiter
Correct Answer: B) Neptune
Explanation: Methane in Neptune’s atmosphere gives it a blue hue.

27. What is the densest planet in the solar system?
A) Earth
B) Jupiter
C) Mercury
D) Venus
Correct Answer: A) Earth
Explanation: Earth is the densest planet in the solar system.

28. Which planet has the smallest mass?
A) Mercury
B) Mars
C) Venus
D) Earth
Correct Answer: A) Mercury
Explanation: Mercury is the smallest and least massive planet.

29. What is the coldest planet in the solar system?
A) Uranus
B) Neptune
C) Saturn
D) Mars
Correct Answer: A) Uranus
Explanation: Uranus has the lowest average temperature.

30. Which planet has the fastest orbital speed around the Sun?
A) Mercury
B) Venus
C) Earth
D) Mars
Correct Answer: A) Mercury
Explanation: Mercury’s proximity to the Sun gives it the fastest orbital speed.

31. What is the name of the largest volcano in the solar system?
A) Mauna Loa
B) Olympus Mons
C) Mount Everest
D) Mount Etna
Correct Answer: B) Olympus Mons
Explanation: Olympus Mons on Mars is the largest volcano.

32. Which planet has the thickest atmosphere?
A) Venus
B) Earth
C) Mars
D) Mercury
Correct Answer: A) Venus
Explanation: Venus has a dense, carbon dioxide-rich atmosphere.

33. What is the main component of the Sun?
A) Oxygen
B) Hydrogen
C) Helium
D) Carbon
Correct Answer: B) Hydrogen
Explanation: The Sun is primarily composed of hydrogen.

34. Which planet has the greatest tilt of its axis?
A) Uranus
B) Neptune
C) Saturn
D) Venus
Correct Answer: A) Uranus
Explanation: Uranus is tilted at about 98 degrees.

35. What is the name of the region between Mars and Jupiter where many asteroids are found?
A) Kuiper Belt
B) Asteroid Belt
C) Oort Cloud
D) Van Allen Belt
Correct Answer: B) Asteroid Belt
Explanation: The Asteroid Belt lies between Mars and Jupiter.

36. Which planet is known for its prominent system of rings and is the second largest planet?
A) Jupiter
B) Saturn
C) Uranus
D) Neptune
Correct Answer: B) Saturn
Explanation: Saturn is the second largest planet and has the most visible rings.

37. What is the smallest planet in the solar system?
A) Mercury
B) Mars
C) Venus
D) Earth
Correct Answer: A) Mercury
Explanation: Mercury is the smallest planet by diameter and mass.

38. Which planet has the slowest rotation on its axis?
A) Venus
B) Mercury
C) Mars
D) Jupiter
Correct Answer: A) Venus
Explanation: Venus rotates very slowly, taking about 243 Earth days for one rotation.

39. What is the name of the process by which a star explodes at the end of its life cycle?
A) Nova
B) Supernova
C) Nebula
D) Quasar
Correct Answer: B) Supernova
Explanation: A supernova is a powerful explosion marking the end of a massive star’s life.

40. Which planet is known as the “Giant Planet” due to its size?
A) Jupiter
B) Saturn
C) Uranus
D) Neptune
Correct Answer: A) Jupiter
Explanation: Jupiter is the largest planet and is often called the “Giant Planet.”

41. What is the name of the faint, outermost layer of the Sun’s atmosphere?
A) Chromosphere
B) Corona
C) Photosphere
D) Mesosphere
Correct Answer: B) Corona
Explanation: The corona is the Sun’s outermost atmospheric layer.

42. Which planet has the most elliptical orbit among the eight planets?
A) Mercury
B) Mars
C) Neptune
D) Uranus
Correct Answer: A) Mercury
Explanation: Mercury’s orbit is the most elliptical among the planets.

43. What is the name of the path that a planet follows around the Sun?
A) Axis
B) Orbit
C) Revolution
D) Rotation
Correct Answer: B) Orbit
Explanation: An orbit is the path a planet follows around the Sun.

44. Which planet is known for its retrograde rotation, spinning in the opposite direction to most planets?
A) Venus
B) Mars
C) Jupiter
D) Saturn
Correct Answer: A) Venus
Explanation: Venus rotates from east to west, opposite to most planets.

45. What is the name of the largest moon in the solar system?
A) Titan
B) Ganymede
C) Callisto
D) Europa
Correct Answer: B) Ganymede
Explanation: Ganymede, a moon of Jupiter, is the largest moon.

46. Which planet is sometimes called the “Ice Giant” along with Neptune?
A) Uranus
B) Saturn
C) Jupiter
D) Mars
Correct Answer: A) Uranus
Explanation: Uranus and Neptune are both classified as “Ice Giants.”

47. What is the name of the process by which planets form from dust and gas in a protoplanetary disk?
A) Accretion
B) Fission
C) Fusion
D) Sublimation
Correct Answer: A) Accretion
Explanation: Accretion is the process of growth by accumulation of dust and gas.

48. Which planet has the greatest number of rings?
A) Saturn
B) Jupiter
C) Uranus
D) Neptune
Correct Answer: A) Saturn
Explanation: Saturn has the most extensive ring system.

49. What is the name of the first spacecraft to land on the Moon?
A) Apollo 11
B) Luna 2
C) Surveyor 1
D) Vostok 1
Correct Answer: B) Luna 2
Explanation: Luna 2 was the first spacecraft to reach the Moon’s surface.

50. Which planet is known for its large, dark storm called the “Great Dark Spot”?
A) Jupiter
B) Neptune
C) Uranus
D) Saturn
Correct Answer: B) Neptune
Explanation: Neptune’s Great Dark Spot is a massive storm system.