Free Astronomy and Space MCQs with Answers
286 Astronomy and Space MCQs from Everyday Science, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Astronomy covers the structure and motions of the solar system, planets, satellites, comets, asteroids and meteoroids, together with gravity, eclipses, seasons and phases of the Moon. It also introduces stars, galaxies, nebulae, black holes, space telescopes and satellites, while distinguishing rotation from revolution and meteors from meteorites.
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286 questions · page 2 of 15
- A. Elliptical
- B. Highly elliptical
- C. Circular
- D. Parabolic
Explanation: Most comets follow highly elliptical orbits, travelling far from the Sun and returning after a period.
Correct answer: Highly elliptical- A. Jupiter
- B. Venus
- C. Mars
- D. Mercury
Explanation: Mercury moves fastest around the Sun because it is the closest planet and has the shortest orbital period, about 88 Earth days.
Correct answer: Mercury- A. Venus
- B. Mercury
- C. Mars
- D. Moon
Explanation: Venus is traditionally identified as Earth's nearest planet because it can come closer to Earth than any other planet.
Correct answer: Venus- A. Oxygen
- B. Hydrogen
- C. Carbon Dioxide
- D. Silicon
Explanation: Hydrogen is the most abundant element in the universe, making up most of the material in stars and much of the interstellar gas.
Correct answer: Hydrogen- A. Star
- B. Planet
- C. Asteroid
- D. Meteor
Explanation: The Sun is a star because it produces its own light and heat through nuclear fusion. Planets and asteroids only reflect light from a star.
Correct answer: Star- A. Mercury
- B. Pluto
- C. Neptune
- D. Uranus
Explanation: Neptune is the outermost of the eight officially recognized planets. Pluto lies farther out at times but is classified as a dwarf planet…
Correct answer: Neptune- A. William Caxton
- B. John Davise
- C. Herschel
- D. Shellay
Explanation: William Herschel discovered Uranus in 1781 while conducting telescopic observations.
Correct answer: Herschel- A. 6
- B. 4
- C. 7
- D. 3Chemistry
Explanation: The Sun is commonly described as having six layers: core, radiative zone, convection zone, photosphere, chromosphere and corona.
Correct answer: 6- A. Less than on Earth due to its lower mass and smaller radius
- B. More than on Earth due to its smaller radius
- C. The same as on Earth because escape velocity is a constant
- D. Dependent on the time of day
Explanation: The Moon’s escape velocity is about 2.38 km/s, compared with about 11.2 km/s for Earth.
Correct answer: Less than on Earth due to its lower mass and smaller radius- A. Mass of the object trying to escape
- B. Radius of the planet or celestial body
- C. Both mass and radius of the planet or celestial body
- D. The velocity of the rotating planet
Explanation: Escape velocity depends on the mass and radius of the attracting celestial body, according to vₑ = √(2GM/R).
Correct answer: Both mass and radius of the planet or celestial body- 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.
Correct answer: 11.2 km/s- 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…
Correct answer: both need the same velocity- 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.
Correct answer: 25 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.
Correct answer: 27.3 days- 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…
Correct answer: 40- 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.
Correct answer: Meteoroids- 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.
Correct answer: Regolith- 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.
Correct answer: Venus and Uranus Chemistry- 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.
Correct answer: Both A and B- 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.
Correct answer: Inner planets (Mercury, Venus, Earth, and Mars)