astronomy_hch

I am copying all of my astronomy paragraphs in here. I am giving them all proper titles. I am adding a picture to go with each paragraph.



//__Fr__////__o__////__m Big Bang to Gal__////__axies__//
===Our universe began about 15 billion years ago in an event called the big bang. In the big bang, our universe exploded from the size of an atomic nucleus into our universe. In the first 10-43 seconds, the universe started to expand rapidly, and pieces of matter were created. By the first 10-4 seconds, the temperature fell there is radiant energy and lighter particles. At one second, the temperature is at 10 billion degrees, and the particles still exist. At three minutes, one fourth of the protons and neutrons created helium nuclei. Finally at 300,000 years the temperature is at 3000 degrees kelvin, and electrons started to orbit protons and hydrogen nuclei. The process of the big bang then started to slow down, and our universe started to into what it is today.===

//__Formations of Galaxies__//
===2 billion years after the big bang, galaxies formed from gravity pulling clumps of matter together. During the formation of galaxies, the universe has a sponge-like structure. Galaxies start as a large sphere of gas, while clusters of stars move=== ===through the sphere, creating the halo of the galaxy. Spiral arms developed from gas settling in the disc of the galaxy. The shapes of the galaxies include elliptical, spiral, or irregular. In the beginning of the universe, galaxies were much closer than they are now. Two or more galaxies crashing into one another can create a single larger galaxy. Galaxies were created from gravity pulling matter together, causing clumps of stars to settle in the disc, or spiral arms of the galaxy.===

Diagram of the Milky Way Galaxy

//__Rotation of the Galaxy__//
===The Milky Way Galaxy spins slowly, with four spiral arms surrounding the central bulge. The spiral arms are made up of blue young stars and pink clouds of hydrogen gas. The central bulge of the Milky Way galaxy is made up of red and orange stars. The red and orange stars inside of the central bulge are old stars that were packed into the bulge. The nucleus of the galaxy is in the center 15 light years of the galaxy, and is an immense black whole with a ring of gas clouds and dust surrounding it. Each star and gas cloud is in its own orbit, which causes the galaxy to look as if it is moving as a whole. The spiral arms of the galaxy are where matter clumps together. Our galaxy is 5 times larger than they appear, because of an invisible corona. Our galaxy is a disc like structure made solids, gas, and dust, spinning in a rotation with four large spiral arms.===



The Milky Way Galaxy

//__Formation__// //__of the Planets__//
===The terrestrial and the giant planets were formed from planetessimals crashing into each other, causing them to clump together and create a planet. About 4.5 billion years ago, planets formed from large solid particles clumping together in a disc of gas and dust surrounding the sun. At first, planets were very close together, until they started to collide and create larger planets. Four large planets formed in the outer solar system, the giant planets. These planets are Jupiter, Saturn, Uranus, and Neptune. Each of these planets has moons orbiting around their disc. Each of these planets mass is about 10 times bigger than the Earth’s. The next planets to form were the terrestrial planets, Mercury, Venus, Earth, and Mars. Each of these planets surfaces were heated from continuous collisions, with the insides of the planets generating radioactive heat. Metal sank to the middle, while light rock rose to the surface, until they cooled off and hardened. Our planets formed from solid particles crashing together are rotating and orbiting every second around the sun, along with all of the other planets in the Milky Way galaxy.===

Our solar system.

//__Formation of Moons, Rings, and Comets__//
===Moons, rings, and comets were all formed from activity from planetessimals. The moon was formed in a collision with the uniformed earth and a planetessimal about the size of mars. The craters in the moon are not natural, they were created from bombardment. Most planetessimals have been destroyed from colliding with other planetessimals, thrown into the outer solar system, or have settled in the asteroid belt. Some existing planetessimals were used as moons for planets. Comets are made when icy planetessimals when they are around the sun. Rings are created when planetessimals and comets are torn apart by the gravity of the giant planets. Venus, Earth, and Mars acquired their atmospheres later than others because of the gases blown out of volcanoes. In the early stages of the universe, it was common for large rocks to crash into the earth. The most recent time a rock crashed into the earth was 65 million years ago, which caused the extinction of many species including dinosaurs. Moons, rings, and comets were formed with explosions and other activities from planetessimals and comets.===



A comet soaring through space.

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