The length of the Milky Way is .......... light years.

Albedo is maximum for

The image shows a diagram of the solar system. Which of the following correctly identifies the planets in the order of their distance from the Sun?

Two stars situated at distances of $1$ and $10$ light years respectively from the earth appear to possess the same brightness. The ratio of their real brightness is

The galaxies are moving away from each other. This phenomenon is explained by:

The faintest stars visible to the naked eye are called: