Astronomy Cosmology and Deep Space 3

Question 1

What is a light-year a measure of?

Accepted Answer

Distance

Answer

A light-year is the distance light travels in one year, about 9.46 trillion kilometers.

Question 2

Which type of galaxy is the Milky Way classified as?

Accepted Answer

Spiral galaxy

Answer

The Milky Way is a barred spiral galaxy with a central bar and winding arms.

Question 3

Dark matter is inferred to exist primarily because of its effect on:

Accepted Answer

The rotation and motion of galaxies

Answer

Galaxies rotate faster than their visible mass allows, implying unseen dark matter provides extra gravity.

Question 4

The nearest major galaxy to the Milky Way is:

Accepted Answer

Andromeda

Answer

The Andromeda Galaxy is the nearest large spiral galaxy and is approaching the Milky Way.

Question 5

What cosmic structure is a vast, mostly empty region between galaxy filaments?

Accepted Answer

A void

Answer

Cosmic voids are enormous low-density regions in the large-scale structure of the universe.

Astronomy Practice Test