Free Astronomy and Space MCQs with Answers

181. Mostly which gases found of the planet Jupiter?

• A. Hydrogen
• B. Chlorine
• C. Hydrogen and Helium
• D. Neon

Explanation: Jupiter is a gas giant composed mainly of hydrogen and helium, with hydrogen making up the larger share. Chlorine and neon are present only in tiny amounts, if at all.

182. NASA scientists have recently detected water vapor on which Jupiter's moon?

• A. Callisto
• B. Europa
• C. lo
• D. None

Explanation: Europa, one of Jupiter’s icy moons, has shown evidence of water vapour associated with possible plumes from its subsurface ocean. Callisto and Io are not the moon intended in this observation.

183. Which planet is called "red planet"?

• A. Mars
• B. Venus
• C. Jupiter
• D. Saturn

Explanation: Mars appears reddish because iron minerals in its surface rocks and dust have oxidized, forming iron oxides. This rusty dust gives Mars its familiar name, the Red Planet.

184. Water has been discovered on which potentially habitable super-Earth ?

• A. K2-14d
• B. K2-15c
• C. K2-13a
• D. K2-18b

Explanation: K2-18b is a potentially habitable super-Earth whose atmosphere has been studied for water vapour and other gases. The similar-looking K2 catalogue names in the other options are the usual distractors.

185. The Saturn rings discovered by___________?

• A. Newton
• B. Robert Brown
• C. Galileo
• D. None of these

Explanation: Galileo first observed Saturn's rings through a telescope in 1610, although his telescope was not powerful enough for him to understand their true nature. Newton and Robert Brown were not the discoverers of the rings.

186. The Planet which revolves slowly around the Sun is__________?

• A. Mercury
• B. Mars
• C. Earth
• D. Neptune

Explanation: Neptune takes about 165 Earth years to complete one orbit, the longest orbital period among the eight planets. Its great distance from the Sun makes its revolution slow compared with the other options.

187. The "Rising" of the "evening star" indicates the direction of the____________?

• A. South Pole
• B. East
• C. West
• D. North

Explanation: Venus is called the evening star when it appears after sunset, and it is then seen in the western sky. The eastern appearance of Venus is called the morning star.

188. Ring planet is Saturn; least dense and 2nd largest planet is_________?

• A. Jupiter
• B. Saturn
• C. Neptune
• D. Mercury

Explanation: Saturn is the second-largest planet after Jupiter and has the lowest average density of all the planets, even less than water. Its extensive ring system is another identifying feature.

189. The matter of our sun is in ________ state?

• A. Liquid
• B. Gas
• C. Solid
• D. Plasma

Explanation: The Sun is mostly ionised hydrogen and helium, in which atoms have lost electrons. This electrically charged state of matter is called plasma, rather than an ordinary gas.

190. Which of the following branch of Physics deals with the internal structure of earth?

• A. Biophysics
• B. Geophysics
• C. Plasma physics
• D. Atomic physics

Explanation: Geophysics applies physics to Earth, including its interior, rocks, gravity, magnetic field, and seismic activity. Biophysics studies living systems, while plasma and atomic physics concern different physical scales.