What are Galaxies?

You’ve probably heard of the Milky Way. If you haven’t, you should know that you live inside of it! Our galaxy was formed billions of years ago and has hundreds of billions of stars that are held together by an immense force known as gravity. Galaxies in general are massive collections of dust, gas, and stars that are held together with the force of gravity

Scientists believe that galaxies were formed after the Big Bang. They say that the universe was once composed of small, subatomic particles and radiation. It is speculated that particles and radiation slowly formed together to create clusters of stars, which would eventually create galaxies. It is also speculated that they formed into giant masses of matter, which would later divide up into smaller galaxies.

Galaxies come in different forms. Some are similar to ours with a large, spiral shape, and they are known as “spiral galaxies”. Those galaxies resemble pinwheels. Other galaxies look like blobs and have shapes that are irregular. These galaxies are known as elliptical galaxies.

When Were Galaxies Discovered?

The idea of the galaxy was proposed by a man named Thomas Wright in 1750. It wasn’t until the early 20th century, though, that the astronomy community believed that the majority of the universe was within the Milky Way Galaxy. A man by the name of Harlow Shapley who was a scientist at the Harvard College Observatory, believe that the spiral-shaped blobs that they had seen across the universe were actually different “island universes”. 

In 1924, Edwin Hubble discovered a variety of pulsating stars, which he dubbed “Cepheid variables”. He said that these celestial objects were far beyond the boundaries of our own galaxy and were made up of unique star collections. He began measuring the distance of these galaxies from our own. When he finished, he measured their Doppler Shift to see how fast they were moving. He eventually concluded that the universe was expanding and there were many other galaxies moving at fast rates beyond ours.

Biggest Galaxy

The largest galaxy that is known to man is known as IC 1101. At just over 6 million light years in diameter, this massive galaxy is located about a billion light years away and is the biggest galaxy that we have ever observed. Its boundaries extend about 2 million light years from its core. In whole, it contains about 100 trillion stars. 

To put all of this into relativity, the Milky Way is about 100,000 light years in diameter. If this galaxy were to move its way into our realm, it would not only swallow our galaxy like a snack, but would also swallow up the Andromeda galaxy, the Triangulum galaxy, and the Magellanic Clouds, as well as all of the space in-between. 

This galaxy was formed thanks to the collisions of many galaxies over billions of years. We can now see that this galaxy is not creating tons of new stars, meaning that if it does not continue to collide with galaxies, it will eventually fade away.

Galaxy Fun Facts

At one point, the Hubble Space Telescope was directed up into a small portion of space to observe and report. In only 12 days, the telescope found about 10,000 different galaxies, each with their own unique shapes and sizes. That fact alone helps us to speculate that there could easily be hundreds of billions of galaxies in the universe.

We now know that our Galaxy will one day smash into the Andromeda galaxy, which is our closest galaxy neighbor. The act of one galaxy bumping into another happens pretty often. Most of the time, planets never even touch, as the outer rims of galaxies are spread so wide that the planets can miss each other all together. Don’t fret though, as scientists don’t expect this to happen for another 5 billion years.

Galaxies rotate incredibly fast, much faster than we can predict based on the gravity that is contained within their stars. The extra gravitational force that we can not predict is said to be from dark matter, of which no light or radiation is emitted.

How Far Is The Nearest Galaxy?

The Milky Way has about 54 neighbors within the Virgo Supercluster. The closest major galaxy in this large cluster is known as the Andromeda Galaxy. This spiral galaxy is very similar to ours, though not technically the closest. The closest galaxy is actually a dwarf galaxy known as the Canis Major Dwarf Galaxy. It lies about 25-thousand light years from the center of our solar system. 

This dwarf galaxy is said to carry around about a billion stars in total and has an elliptical shape. Behind it is a large filament of stars that shoots out like a long galactic trail. Scientists refer to this structure as the Monoceros Ring.

Latest Galaxy News

In 2018, a new image from the Hubble Telescope was able to string together about 15,000 different galaxies, which was one of the largest discoveries in galaxy history. Scientists say this will provide enough hunting ground for years of galactic study. In the same period, there were hundreds of galaxies discovered behind a massive black hole. Up until 2018, that black hole was blocking their light.

Astronomers have just recently discovered a new neighboring galaxy that is in the global cluster known as NGC 6752. This new dwarf galaxy is known as Bedin 1 and it is obscured by the globular cluster of stars. Thanks to the Hubble Telescope, this small globular star cluster, located about 13,000 light years away from the edge of the Milky Way, was discovered. Check out this video of the telescope zooming in on Bedin 1 and the surrounding cluster.