Irregular galaxy

High school (ages 12+)
Space & Astronomy

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/irregular-galaxy

1. What is the cosmic abundance?
2. What makes an irregular galaxy look different from a spiral or elliptical galaxy?
3. Why do irregular galaxies often have no spiral arms?

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the cosmic abundance?Estimated to constitute approximately 25% of all observed galaxies in the universe
2. What makes an irregular galaxy look different from a spiral or elliptical galaxy?Irregular galaxies don't have a clear shape like a bulge or spiral arms, so they look like chaotic splatters of stars and gas.
3. Why do irregular galaxies often have no spiral arms?Their chaotic shape means they don't have the density waves that create spiral arms, so the stars are spread out more randomly.

Hubble Sequence: A classification system for galaxies based on their visual morphology, developed by Edwin Hubble.
Tidal Forces: Gravitational forces exerted by a celestial body that vary across its diameter, causing distortion.
Density Waves: Large-scale, spiral-shaped disturbances in a galaxy's disk that compress gas and trigger star formation.
Interstellar Medium (ISM): The matter and radiation that exist in the space between the star systems of a galaxy.