The video introduces galaxies, explaining their types and characteristics. It covers the discovery of galaxies beyond the Milky Way by Edwin Hubble and describes the three main types of galaxies: spiral, elliptical, and irregular. Spiral galaxies, like the Milky Way, have a central bulge and spiral arms. Elliptical galaxies are older and formed from merging smaller galaxies. Irregular galaxies lack a defined shape. The video encourages viewers to help classify galaxies through Galaxy Zoo, highlighting the importance of human input in scientific research.

What did Edwin Hubble discover about the universe in the 1920s?

• The universe is smaller than previously thought.

• There are multiple galaxies beyond the Milky Way.

• Galaxies do not change shape over time.

• The Milky Way is the only galaxy.

What is a defining feature of spiral galaxies?

• They have a supermassive black hole at the center.

• They are perfectly round.

• They contain only old stars.

• They lack a galactic disk.

Where in the Milky Way is our solar system located?

• In the Orion spur

• In the Galactic bulge

• In the Large Magellanic Cloud

• In the center of the galaxy

What is the difference between spiral and barred spiral galaxies?

• Spiral galaxies do not have a Galactic bulge.

• Barred spirals have a bar through the Galactic bulge.

• Spiral galaxies have no stars.

• Barred spirals are perfectly round.

What is a characteristic of elliptical galaxies?

• They are the youngest galaxies.

• They have a lot of gas and dust.

• They are formed from merging spiral galaxies.

• They have a spiral structure.

What is the future event involving the Milky Way and Andromeda galaxy?

• They will lose all their stars.

• They will remain separate forever.

• They will collide to form a new galaxy.

• They will both become irregular galaxies.

What is a common feature of irregular galaxies?

• They contain only new stars.

• They often look chaotic.

• They have a well-defined shape.

• They are always larger than spiral galaxies.

What are satellite galaxies?

• Galaxies that are only found in the Milky Way.

• Galaxies that orbit larger galaxies.

• Galaxies that are perfectly round.

• Galaxies with no stars.

How can you contribute to galaxy classification from home?

• By using Galaxy Zoo to classify images.

• By building your own telescope.

• By reading astronomy books.

• By visiting a local observatory.

Why do machines sometimes need human help in classifying galaxies?

• Machines are not used in astronomy.

• Machines can get confused with complex images.

• Humans can see more colors than machines.

• Machines are too slow to process images.