Scientists and Astronomers do not know the exact reason, but with the help of new technology, they can begin to look into the past of the universe.
Galaxy formation and star formation are very similar. They both include a molecular cloud collapsing under its own weight. Galaxies form from much larger clouds because they are much larger than stars. To help paint the picture, there are billions and billions of stars in one galaxy alone.
Galaxy formation and star formation are very similar. They both include a molecular cloud collapsing under its own weight. Galaxies form from much larger clouds because they are much larger than stars. To help paint the picture, there are billions and billions of stars in one galaxy alone.
Spiral Galaxy Formation
Bodies of gas, dust, and young stars collide. As this happens, the stars rotate around the mass because of the gravitational force. As everything else starts to rotate, the cloud contracts, thus creating a "Galactic Disk" A Galactic Disk is just a disk containing mostly younger stars, dust, and gas. The motion of the rotation causes the "arms" to form. This type of galaxy is the most common type of galaxy.
Irregular Galaxy Formation
Irregular galaxies start off as "normal" galaxies, or ones that fall in to the Hubble Sequence. The Hubble Sequence is a classification of galaxies created by Edwin Hubble in 1936. As they collide or come close to other galaxies, their gravity's take effect on each other. As this happens, their shape become distorted.
Elliptical Galaxy Formation
Elliptical Galaxies are created by two spiral galaxies colliding. These galaxies contain older stars and gasses. Star formation is low in these galaxies. Scientists believe that a super-massive black hole is at the center of these very old galaxies. Due to being formed from collision, these galaxies are most commonly found around galaxy groups and clusters. They are not commonly found in the "early" universe: there were not many galaxies at this time.
Quiz
1. This galaxy is the most common type of galaxy.
2. This type of galaxy starts off as a "normal" galaxy.
3. True of False: The Hubble Sequence is a classification of galaxies created by Edwin Hubble.
4. True or False: Scientists know the exact reason of how galaxies formed.
5. Irregular galaxies shapes are formed by other galaxies .