It seems the Milky Way Galaxy
is just one of BILLIONS
A galaxy is a collection of stars held together as a group by gravity. The Milky Way galaxy is the galaxy we live in and it is classified as a "spiral" galaxy. There are 3 types of space galaxies; spiral, elliptical, and irregular. You guessed it... these names are based on the shape a galaxy takes!
Classified by shape
Spiral galaxies, such as our galaxy, take on a spiral shape and appear to be "swirling" as a group in outer space. Elliptical galaxies resemble a "flattened ball" or circular formation, the stars found in elliptical galaxies are also much older than those in spiral galaxies.
Irregular galaxies are those that don't really take on any sort of shape. Often, two galaxies may merge together. A merging disrupts the original orbit of stars and planets, this is sometimes what causes a galaxy's shape to appear "irregular."
The discovery of other galaxies
In 1924 the famous astronomer Edwin Hubble proved the existence of several other far off galaxies. Little did he know just how many! In 1977 NASA starting building their most advanced space telescope ever and named it after Edwin. The Hubble Telescope was launched in 1990 and still orbits outside Earth's atmosphere today.
A bigger picture!
Not only has the Hubble Telescope confirmed the existence of other galaxies, but it has provided images that will help us understand exactly how big the universe really is. Hubble's "Ultra Deep Field" image revealed more than 10,000 new galaxies! Astronomers now estimate the existence of BILLIONS of galaxies!
Here are some additional facts about Galaxies:
*One galaxy can contain millions, even billions, of stars! The Milky Way alone contains over 200 billion!
*There is a supermassive Black Hole at the center of the Milky Way galaxy!
*Similar to how stars group together to form a galaxy, galaxies often neighbor several others to form a group of galaxies.
*Our galaxy is grouped with about 30 other galaxies and they're referred to as "The Local Group."
Return to the kids Outer Space page!