The Milky Way

Who discovered the Milky Way?
Democritus was the first person in recorded history to make the assumption that the Milky Way was up of billions of stars.
Milky Way

When was the Milky Way discovered?
Some time with in Democritus lifetime. 460 BC – 370 BC. Edwin Hubble later discovered that Andromeda, which was believed to be in the Milky Way, was a separate galaxy. This was a break through.

How was the information gathered?
Information was gathered all throughout history. With better technology, and more powerful telescopes, we have been able to make many discoveries about our galaxy. When the first telescopes came out they start studying the star clusters that they were seeing. In 1775, Immanuel Kant speculated (correctly) that the Milky Way may be a huge body of stars rotating. Then Hubble came around with his new telescope and he made many observations on the galaxy

How does this help us today?
This information helps us because this shows us how big and vast our universe is. We can now see other galaxies and see how small we are compared to everything. Our star (the sun) is only a tiny little speck in the Milky Way. And earth is even smaller.

What makes the Milky Way special?
It's 26,000 light-years from Earth and Sgr A* is measured to be about 14 million miles across. This means that the black hole itself would easily fit inside the orbit of Mercury. How much mass is crammed inside this relatively small space? The lower mass limit of the black hole itself is calculated to be more than 40,000 Suns. However, the radio-emitting part of Sgr A* is a bit bigger, about the size of the Earth's orbit around the Sun (93 million miles), and weighs much, much more – 4 billion Suns.

New Discoveries?
The Black Hole, and how powerful it is.

How big is the Milky Way?
The stellar disk of the Milky Way galaxy is approximately 100,000 light years in diameter.
What type of galaxy is it?
It is a Spiral galaxy

My thought.
I think that this is a very interesting topic. I like learning about the galaxy that we live in. It amazes me that there are billions of stars in the Milky Way. We orbit one out those billions of stars. There has to be other life out there. It could just be little organisms like bacteria.

My questions.
Are there any planets that are similar to the planet earth in our galaxy?
If so… how far away is it?

What I want to know.
I want to know if we are going to be able to land on another planet that is in a different solar system then ours. (in the Milky Way)
Changes in thoughts.
This really changed my thought process about the universe and our galaxy. It amazes me that we think that we are the center of the universe when there are countless numbers of stars out there.

Work Sited NatSci102/lectures/milkyway.htm