Galaxy Formation

A group of billions of stars and their planets, gas, and dust that extends over many light-years and forms a unit within the universe.

Held together by gravitational forces

Early astronomers observed these “spiral nebulae” and most believed them to be clouds of gas and stars within our own galaxy.

In 1924, Edwin Hubble was able to measure the distance to the “Great Nebula in Andromeda” and found its distance to be much larger than the size of the Milky Way. 

Hubble divided galaxies into different “classes” based on their appearance.

These are part of the "basic language" of Physics.

Have long arms winding toward a bright bulge at the center.

The difference between tightly and loosely wound spirals can be used to classify spiral galaxies.

About 77% of the observed galaxies in the universe are spiral galaxies.

Shaped like a squished circle.

Elliptical galaxies are classified by how stretched out they are.

The most abundant type of galaxies found in the universe but because of their dim qualities, they're often outshone by other galaxies

The catchall name given to any galaxy that does not neatly fit into one of the other categories.

They have no defined shape nor structure and may have formed from collisions or violent activity. 

Some of the smallest galaxies and are full of gas and dust, signifying star formation.