Basic Astronomy

Question 1

Our Milky Way galaxy is what kind of galaxy?

Accepted Answer

A spiral galaxy

Answer

Our Milky Way galaxy is classified as a barred spiral galaxy. It features a central bar-shaped structure composed of stars, from which spiral arms extend outwards. This characteristic shape is common among large galaxies and is determined by the distribution of stars, gas, and dust within the galaxy.

Question 2

Which planet is the biggest among these?

Accepted Answer

Jupiter

Answer

Jupiter is the largest planet in our solar system by a significant margin. Its diameter is about 11 times that of Earth, and its mass is more than twice the mass of all the other planets combined. This gas giant is easily identifiable by its immense size and prominent atmospheric features, such as the Great Red Spot.

Question 3

What will ultimately happen to our sun?

Accepted Answer

White dwarf

Answer

Our Sun, a main-sequence star, will eventually exhaust its hydrogen fuel. It will then expand into a red giant, shed its outer layers to form a planetary nebula, and finally collapse into a dense, hot stellar remnant called a white dwarf. This is the typical end stage for stars of the Sun's mass, rather than becoming a black hole or fireball.

Question 4

To what extent is the galaxy visible in the night sky?

Accepted Answer

0.03%

Answer

Due to our position within the Milky Way galaxy and the presence of interstellar dust and gas that obscure our view, only a very small fraction of our own galaxy is directly visible from Earth. We can see the galactic plane as the 'Milky Way' band in the night sky, but the vast majority of the galaxy's structure and stars are hidden from our direct observation.

Question 5

What is the number of galaxies in the universe that can be observed?

Accepted Answer

200 billion

Answer

Current astronomical estimates suggest that there are approximately 200 billion galaxies in the observable universe. This number is derived from deep-field observations by powerful telescopes like Hubble, which reveal countless galaxies in even tiny patches of sky. Each of these galaxies, in turn, contains billions of stars, making the universe incredibly vast.

Astronomy Practice Test

Astronomy Practice Test

Basic Astronomy