Galaxy

The video explains galaxies as massive systems of stars, gas, and dust held together by gravity. It covers the three main types of galaxies: spiral, elliptical, and irregular, highlighting their unique characteristics. Spiral galaxies, like the Milky Way, are rich in gas and young stars, while elliptical galaxies contain older stars and less gas. Irregular galaxies lack a defined shape but have active star formation. The video also discusses galaxy distribution in space, noting that galaxies often cluster together. Finally, it poses a thought-provoking question about the solar system's journey around the Milky Way's center.

What is the primary force that holds a galaxy together?

• Nuclear force

• Magnetism

• Gravity

• Electromagnetic force

Which type of galaxy is characterized by spiral arms extending from its center?

• Spiral galaxy

• Barred galaxy

• Elliptical galaxy

• Irregular galaxy

What percentage of galaxies are spiral galaxies?

• 10%

• 20%

• 30%

• 40%

Which type of galaxy is mostly composed of older stars and has little new star formation?

• Barred spiral galaxy

• Irregular galaxy

• Elliptical galaxy

• Spiral galaxy

What is the shape of elliptical galaxies?

• Elliptical

• Irregular

• Spiral

• Circular

Which type of galaxy lacks a defined shape and is rich in gas and dust?

• Barred spiral galaxy

• Elliptical galaxy

• Spiral galaxy

• Irregular galaxy

What is the name of the galaxy cluster that includes the Milky Way?

• Coma Cluster

• Andromeda Group

• Local Group

• Virgo Cluster