Astronomy, part V : Galaxies.
A star is simply a space object that emits energy in the form of heat and light and is composed of gas and dust attracted to each other via the force of gravity.
Astronomy 101
05 GALAXIES
Galaxies are massive groupings of stars and gas and dust. Our sun is in the Milky Way galaxy, which measures approximately 100,000 light years across.
Our spiral galaxy is made up of several billion stars. Sobering. Want something more sobering?
The Milky Way is one galaxy that has hundreds of billions of stars. Again, we are one galaxy.
And there are at least a few hundred million galaxies in the universe. Each with hundreds of billions of stars.
Think on that.
Think the world still revolves around you and your problems?
You are tiny. So am I.
Spiral
Yeah, that’s us. Galaxies that have spiral arms coming out from the center. Our solar system is on one of the spiral arms of the Milky Way. Good thing we’re on an arm and not the center. What’s in the center?
A big black hole.
Elliptical
Elliptical galaxies are shaped like a big egg.
Irregular
These are pretty much every kind of galaxy that’s shaped differently than a spiral or elliptical.
Again, we are one galaxy.
One galaxy of many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
many, many, many, many, many, many, many, many, many, many, many, many, many,
galaxies.