Astronomy Astronomy MCQ 2 — Questions and Answers
Question 1: Which planet has the shortest orbital period around the Sun?
- Mercury (Correct answer)
- Venus
- Earth
- Mars
Correct answer: Mercury
Mercury is closest to the Sun and completes an orbit in about 88 Earth days.
Question 2: What is the name of the boundary around a black hole beyond which nothing can escape?
- Photosphere
- Event horizon (Correct answer)
- Chromosphere
- Roche limit
Correct answer: Event horizon
The event horizon marks the point of no return where escape velocity exceeds the speed of light.
Question 3: Which type of galaxy has a flattened disk with spiral arms?
- Elliptical
- Irregular
- Spiral (Correct answer)
- Lenticular
Correct answer: Spiral
Spiral galaxies feature a central bulge surrounded by a disk of arms, like the Milky Way.
Question 4: What causes the phases of the Moon?
- Earth's shadow on the Moon
- The Moon's changing distance
- The relative positions of the Sun, Earth, and Moon (Correct answer)
- Clouds in Earth's atmosphere
Correct answer: The relative positions of the Sun, Earth, and Moon
Phases result from how much of the sunlit half of the Moon faces Earth as it orbits.
Question 5: Which element is most abundant in the Sun?
- Helium
- Oxygen
- Hydrogen (Correct answer)
- Carbon
Correct answer: Hydrogen
Hydrogen makes up about three-quarters of the Sun's mass and fuels its fusion.
Question 6: What unit is defined as the average distance from Earth to the Sun?
- Light-year
- Parsec
- Astronomical unit (Correct answer)
- Angstrom
Correct answer: Astronomical unit
One astronomical unit (AU) equals roughly 93 million miles.
Question 7: Which planet is known for its prominent ring system?
- Jupiter
- Saturn (Correct answer)
- Uranus
- Neptune
Correct answer: Saturn
Saturn's bright, extensive rings of ice and rock are its most recognizable feature.
Astronomy Astronomy MCQ 2
Which planet has the shortest orbital period around the Sun?