Free Astronomy and Space MCQs with Answers

31. What is the escape velocity on Earth?

• A. 7.9 km/s
• B. 9.8 km/s
• C. 11.2 km/s
• D. 12.4 km/s

Explanation: Escape velocity depends on Earth’s mass and radius, not on the mass of the escaping object, and is about 11.2 km/s at the surface. The 9.8 km/s option is the value of gravitational acceleration, not escape velocity.

32. Pen and a home which will need more velocity to escape from the earth?

• A. pen needs less velocity
• B. home needs more velocity
• C. both need the same velocity
• D. none

Explanation: Ignoring air resistance, a pen and a house require the same escape velocity because escape velocity depends on the Earth’s mass and radius, not on the object’s mass. Their energies would differ, but the required speed is the same.

33. The sun completes one full rotation at its equator in how many days?

• A. 365 days
• B. 30 days
• C. 25 days
• D. 23 days

Explanation: The Sun rotates differentially, taking about 25 days to rotate once at its equator. Its rotation is slower near the poles, so 25 days is the equatorial value rather than the 365-day orbital period.

34. The moon rotates on its axis in how many days?

• A. 14.8 days
• B. 17.5 days
• C. 29.7 days
• D. 27.3 days

Explanation: The Moon takes about 27.3 days to rotate once on its axis, equal to its sidereal orbital period around Earth. This synchronous rotation causes nearly the same lunar face to remain directed toward Earth.

35. How many countries are signatories of NASA's Artemis Accords as of May 2024?

• A. 29
• B. 30
• C. 40
• D. None of These

Explanation: The Artemis Accords reached 40 signatory countries in May 2024, setting shared principles for peaceful and sustainable exploration of the Moon, Mars and beyond. The figure is a count of countries, not a count of NASA missions.

36. The moon's surface is constantly bombarded by?

• A. Comets
• B. UV light
• C. Meteoroids
• D. All of the above

Explanation: Meteoroids continually strike the Moon and form many of its craters because the Moon has no substantial atmosphere to burn them up. UV light reaches the surface, but comets do not constantly bombard it, so “all of the above” is not suitable.

37. The moon's surface is also covered with a layer of fine dust called?

• A. Gegolith
• B. Megolith
• C. Regolith
• D. None of the above

Explanation: Regolith is the loose, powdery layer of dust and broken rock covering the Moon’s surface, produced mainly by countless meteorite impacts.

38. Which planets rotate in the opposite direction of the other planets?

• A. Saturn and Jupiter
• B. Jupiter and Neptune
• C. Saturn, Jupiter and Mercury
• D. Venus and Uranus Chemistry

Explanation: Venus and Uranus have retrograde rotation, meaning they spin opposite to the usual direction of planetary rotation. The word “Chemistry” after option d is an editing error, not part of the answer.

39. Terrestrial planets in solar system are made of____________?

• A. Metal
• B. Rock
• C. Both A and B
• D. None of the above

Explanation: Terrestrial planets have solid surfaces and are composed mainly of silicate rock with metallic cores. Therefore, both rock and metal are present.

40. Which four planets are also called the terrestrial planets?

• A. Inner planets (Mercury, Venus, Earth, and Mars)
• B. Outer planets (Jupiter, Saturn, Uranus, and Neptune)
• C. Inner planets (Mercury, Venus) and outer planets (Uranus, Neptune)
• D. Inner planets (Earth, Mars) and outer planets (Jupiter, Saturn)Astronomy

Explanation: The terrestrial planets are the four inner planets, Mercury, Venus, Earth and Mars. They are rocky and relatively small compared with the outer planets.