astronomy_spf

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.

=The Importance of Astronomy in the Search for Life on Mars=

From Big Bang to Galaxies

The big bang theory suggests that the world started off as nothing. The universe was extremely hot and then cooled down quickly so that atoms like quarks and antiquarks could form. When they did, they started to combine to make other atoms that would form the universe. At the beginning of the cooling, the particles wouldn't stick together and was just gas. It became thicker and turned into thick fog. The temperature kept falling quickly until most atoms could bond and turn into matter and would lift the fog. After a long period of time, galaxies started forming.



Formation of Galaxies

Galaxies are groups of stars and planets; groups that have clustered and stayed together in a disk. They start as gas and then clump. Stars stay around the outside of the galaxy as the halo. They are centered around the central bulge which is a void with gas around it. The shapes of galaxies are elliptical, spiral, or irregular. They can bond with each other or they can collide. Either one results in the galaxies making a new galaxy.



Structure of the Galaxy

The galaxy is structured around the central bulge. It is made of a disk, gas, dust, central bulge, planets, and stars. There are many old stars inside of the central bulge. Then there is a nucleus. Around the central bulge, there is a disk all the way around it. Around the disk is gas and dust. There are stars all around it called a halo. Also, within the galaxy, there is a dwarf galaxy merging with our galaxy. It has four spiral arms made of pink clouds of hydrogen gas and blue young stars. The structure of our galaxy is like a disk with many things inside of it.



Rotation of the Galaxy

The galaxy rotates. The spiral arms move around in a counter clockwise. The arms and bulge move different ways. The bulge pulls stars into it while the arms turn the other way. Our galaxy moves this way.



Formation of the Planets

Our planets all started from gas and debris caught in orbit around the sun. The sun was formed first and had a ring of gas and dust around it that became a disk. Solid pieces of matter collected into clumps. They became known as planetessimals. Cold planetessimals could survive in the outer area of the sun's disk because it was cooler. The planetessimals collided where some broke and some stayed. They turned into the giants that we have today like Jupiter, Saturn, Uranus, and Neptune. Planets were made by collision and gas.



Formation of Moons, Rings, & Comets

Moons, rings, and comets were formed by planetessimals, gas, and collision. The moon was created by a collision of a giant planet and the moon. Smaller moons of planets were just planetessimals that caught orbit of other planets. Comets were made from the icy planetessimals that caught on fire after getting too close to the sun. Rings are what happened when planetessimals got too close to planets with strong gravity that pulled them apart. Our moons, rings, and comets were all originally planetessimals.



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