Astronomy Astronomy MCQ 2

Question 1

Which planet has the shortest orbital period around the Sun?

Accepted Answer

Mercury

Answer

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?

Accepted Answer

Event horizon

Answer

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?

Accepted Answer

Spiral

Answer

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?

Accepted Answer

The relative positions of the Sun, Earth, and Moon

Answer

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?

Accepted Answer

Hydrogen

Answer

Hydrogen makes up about three-quarters of the Sun's mass and fuels its fusion.

Astronomy Practice Test