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American Museum of Natural History

Course: American Museum of Natural History > Unit 2

Lesson 3: Galaxies

Formation and evolution of galaxies

In the early universe, there were no galaxies. Today, there are many billions. How did they form? Astronomers use the fundamental laws of physics to deduce the basic story of galaxy formation. Galaxies form out of immense clouds of gas that collapse and rotate. As they evolve, stars form within them. Entire galaxies can collide, changing their appearance. Looking deep into space, we see galaxies at earlier stages in their lives, and learn more about their evolution. They are more numerous, display unusual shapes, and have episodes of energetic outbursts. Galaxies can be seen back to more than 10 billion years ago.

Processes in galaxy formation

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Anthony Jacquez
Posted 9 years ago. Direct link to Anthony Jacquez's post “What is the average size ...”
What is the average size of a galaxy?
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(6 votes)
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- Doran Rahne
  Posted 9 years ago. Direct link to Doran Rahne's post “The Milky Way is 100,000 ...”
  The Milky Way is 100,000 to 120,000 light years across.
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  (1 vote)
datkawaiimelon
Posted 3 years ago. Direct link to datkawaiimelon's post “Where do the spirals come...”
Where do the spirals come from? And what causes the waves to glow?
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(5 votes)
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- Lucas
  Posted 5 months ago. Direct link to Lucas's post “everthing”
  everthing
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  (1 vote)
jsmorris008
Posted 2 years ago. Direct link to jsmorris008's post “question if the gravity s...”
question if the gravity stopped working even in space to what would happen?Where would all the planets go?
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(3 votes)
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Building Sensei
Posted 9 years ago. Direct link to Building Sensei's post “are there exoplanets in o...”
are there exoplanets in other galaxies?
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29lwelch
Posted 5 months ago. Direct link to 29lwelch's post “how do they explode”
how do they explode
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smdvmx
Posted 8 years ago. Direct link to smdvmx's post “How old is the Milky Way,...”
How old is the Milky Way, and how many rotations has it made until now?
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- Andrew Christie
  Posted 6 years ago. Direct link to Andrew Christie's post “A few thousand years old ...”
  A few thousand years old - just look at the genealogy in the Bible.
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turtlefreddy on snapchat
Posted 5 months ago. Direct link to turtlefreddy on snapchat's post “why does the first one lo...”
why does the first one look like someone zoomed in on veins in the human eye😆
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- Lucas
  Posted 5 months ago. Direct link to Lucas's post “stare into my soul”
  stare into my soul
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  (1 vote)