How Galaxies Are Formed

The universe was created 10 to 20 billion years after the Big Bang when clouds of gases collided and compressed against each other. After this explosion, clouds of gases began to merge, collapse, and compress under gravity and galaxies began to form all over the universe. Scientists have different opinions and theories on how galaxies formed. Many believe that the Big Bang started the universe while others believe that smaller clusters of about one million stars, which are called global clusters, formed first and later came together to create galaxies. Other scientists strongly protest against other ideas that that galaxies formed first and that only later did the stars within them begin to gather into smaller clusters. Therefore, there has

At that time, Dr. Hubble had the best telescope and technology equipment up in Mount Wilson. There he figured out that the farther a galaxy was from Earth, the faster it seemed to move away. This was used as a small evidence in proving the Big Bang theory. The idea that the universe was growing, hinted that there may be a possibility that in the beginning of time, there was an immense explosion that caused the universe to dramatically expand. As a result, the Big Bang is the most widely accepted theory for the creation of the universe.

As of right now, there are at the least one hundred billion galaxies roaming in our perpetually expanding universe. Galaxies are countless solar systems that are composed of dust, gas, and stars. There are three main types of galaxies. The spiral, elliptical, and irregular galaxies.

Spiral galaxies are composed of spherical structures in the center called the bulge, which is surrounded by disks that create arm shaped structures. The third part of spiral galaxies are the halo, which can be found in between the bulge and the

E0 represents a perfectly extended galaxy while an E7 elliptical galaxy is flat. Since elliptical galaxies are created by collisions of galaxies, they are found in groups or clusters of galaxies. Furthermore, elliptical galaxies were not common in the early universe, which solidifies the idea that they were developed from the collisions that came later with the formation of galaxies. Elliptical galaxies are just as their name suggests. They are commonly circular, but one axis can be longer than the other. They can be nearly circular or so lengthened which can make them sometimes take on a cigar-like appearance. Elliptical galaxies can contain up to a trillion older stars and little dust and other interstellar matter. Their stars orbit the galactic core, just like the disks of spiral galaxies, but in more random directions. The universe's largest known galaxies, elliptical galaxies, can be as much as two million light-years long. Elliptical galaxies can also very small. These small elliptical galaxies are referred to as dubbed dwarf elliptical