1. The Universe...

2. During the early 1900's, which is not very long ago, astronomers were unaware that there were other galaxies outside our own Milky Way Galaxy. When they saw a small fuzzy patch in the sky through their telescopes, they called it a nebula. When examined closely, some of the nebulae had a spiral shape. So astronomers at first called these "spiral nebulae". These nebulae were all believed to be part of our Galaxy, our community of stars.
Edwin Hubble studied the "spiral nebulae" and found that they were composed of stars. These nebulae were not nebulae at all, but other communities of billions of stars held together by gravity - galaxies! Suddenly, our universe was much bigger. We realized that our Galaxy was just one of many billions of galaxies in the universe.

3. What??
The term Universe is used to describe everything. All that has existed and all that will exist!!
FOOD FOR THOUGHT
-There is nothing beyond The Universe, because if there was, it too, would be part of The Universe!
--We can’t study what came before The Universe, because that is when time began. Astrophysicists show that time and space are the very same thing!
-95% of the atoms in The universe are Hydrogen atoms.
-Some think there is a single universe – others think it is part of a multiverse – one among an infinite amount of others. There is, of course, no way to test this hypothesis.
-Cosmology is the study of the history of The Universe and how it operates.

4. Most galaxies belong to clusters.
The universe is home to billions of Galaxies – each containing billions of stars as you know. The space in between these galaxies is virtually empty of all matter and is termed intergalactic space.
It is thought to resemble a “web” if viewed from such a vantage point – with areas of matter (galaxies) and space.
Most galaxies belong to clusters.
The Milky Way is part of a cluster of about 30 galaxies called the Local Group. Our closest neighbors (170,000 light years away) - the two small Magellenic Clouds can only be seen from the Southern Hemisphere. How do you suppose they where named??
Large and Small Magellenic Clouds

5. The largest member of the Local Group is Andromeda, a spiral galaxy like ours. Andromeda is about 2.2 million light-years away
With about 300 billion stars, its gravitational pull causes several smaller satellite galaxies to orbit around it. Two of these elliptical satellites can be seen with a small telescope.
The Andromeda galaxy is moving toward the Milky Way at about 186 miles per second. It would take about 2 billion years, but it is possible that the two galaxies could collide or merge into each other.

6. Our Local Group along with the Large Virgo Cluster and 100’s of other Galaxy Clusters make up an even larger group called the Virgo Super Cluster!
Confused Yet??
The Virgo Cluster of Galaxies

7. As we look further and further out we see literally countless other galaxies and clusters of galaxies....
The Hubble Telescope focused on a small “boring” part of the sky and took a photo of an area equivalent to what you would see if you looked through an 8 foot soda straw. This is what we found:
Why is looking further into space the very same as looking back in time???

8. There are many sizes and shapes of galaxies
Elliptical -
Spiral - M51
Barred Spiral – M95
Elliptical – M87
ARP 272 is a collision between two spiral galaxies, NGC 6050 and IC 1179, and is
Irregular – NGC1427A
located in Hercules.

17. How did all of this start??
Evidence and observations have overwhelmingly convinced the scientific community that around 14 billion years ago, a tremendous energetic event started the expansion of the universe. This is known as the Big Bang. All of the matter and energy in space was contained in one tiny point. What we see and measure today represents billions of years of continuing expansion from this single point.

18. What evidence is there?
Big Bang Theory - Common Misconceptions There are many misconceptions surrounding the Big Bang theory. For example, we tend to imagine a giant explosion. Experts however say that there was no explosion; there was (and continues to be) an expansion. Rather than imagining a balloon popping and releasing its contents, imagine a balloon expanding: an infinitesimally small balloon expanding to the size of our current universe.
Galaxies appear to be moving away from us at speeds proportional to their distance. This is called "Hubble's Law," named after Edwin Hubble ( ) who discovered this phenomenon in 1929 using the DOPPLAR REDSHIFT. This observation supports the expansion of the universe and suggests that the universe was once compacted.
If the universe was initially very, very hot as the Big Bang suggests, we should be able to find some remnant of this heat. In 1965, Radioastronomers Penzias and Wilson discovered a Cosmic Microwave Background radiation (CMB) which spans the observable universe. This is thought to be the remnant which scientists were looking for. They shared in the 1978 Nobel Prize for Physics for their discovery.
In fact you can see CMB for yourself! If you tune your TV set between channels, a few percent of the "snow" that you see on your screen is noise caused by the background of microwaves.

19. Supermassive Black Holes – Larger and more destructive than their smaller cousins. Most galaxies, including our own Milky Way are thought to have Supermassive Black Holes in the center.
Quasars give off enormous amounts of energy - they can be a trillion times brighter than the Sun! Quasars are believed to produce their
energy from Supermassive Black Holes in the center of the galaxies in which the quasars are located.