Global Science: The Final Exam ( the Earth in Space)

a)
Our Galaxy is a spiral galxay. Our glalaxy is called the Milky Way Galaxy. Our Solar System is near the outside Orian arm of the Spiral Galaxy. Earth is about 30,000 light years away form the center of our Spiral Galaxy. Our sloar systems moves with our galaxy. Our solar system moves with our galaxy. so when the galaxy rotates the solar system stays in the same part of the orain arm and moves with the arm. while that's happening the planets are still orbiting around the sun. the size of the milky way galaxy is about 60,000 light years across. Now the Structure of our galaxy. our galaxy is a spiral galaxy that has over 4oo billion stars, gas and dust, bur more importantly our solar system. A spiral glaxay has a cirular center called the nuclear bulge, or the galactic center. then that arms that come off the center is where our solar system is found. our solar systems sturctuer has the sun in the center and the plnets orbit around the sun. the order of the planets are mercury, venus, Earth, mars, jupiter,saturn,uranus, neptune, next would be pluto but it is no longer a planet. but becasue the plnets are at diffrent distances it takes plnets diffrent amouts of time to orbit around the sun. it takes Earth one year where it takes neptune about 250 to orbit around the sun once. there are predictions that the universe is 10 to 20 billion years old where as Earth is somewhere around 4.5 billion years old.

b)
The Big bang Theory had a lot of influance on the formation of the universe. the big Bang theory is a theory meaning that is was proven several times but theres still a very slim chance taht it's wrong. But the big bang thoery is when there was a big explosion cauesing the formation of the univerves like our own solar system. when this expolsion happened it caused a creation of our plents which makes up our solar system. The explosion also caused gases to be realsed into the atmoshpere. but it helped with formation because when the explotion happend rocks where blown off that made our planets. so it helped with the formation of our universe.

c)
"In 1963, Arno Penzias and Robert Wilson, two scientists in Holmdale, New Jersey, were working on a satellite designed to measure microwaves. When they tested the satellite's antenna, they found mysterious microwaves coming equally from all directions. At first, they thought something was wrong with the antenna. But after checking and rechecking, they realized that they had discovered something real. What they discovered was the radiation predicted years earlier by Gamow, Herman, and Alpher. The radiation that Penzias and Wilson discovered, called the Cosmic Microwave Background Radiation, convinced most astronomers that the Big Bang theory was correct. For discovering the Cosmic Microwave Background Radiation, Penzias and Wilson were awarded the 1978 Nobel Prize in Physics. "
(http://skyserver.sdss.org/dr1/en/astro/universe/universe.asp)
So because the cosmic microwave found thesse misterious waves that helped back up the big bang theory even more. the misterious waves were almost like an echo of the big bang theroy even after all of thesse years. so because the cosmic microwave is picking up thesse waves from the big bang theory thosse waves can be dated back to when it actully happened because if the waves are happening because of the bigbang thorey than you can know the age or hoe long ago our univesre was made. so that's how the cosmic microwave was used to determine that age of our univesre.
PICTURES

https://www.msu.edu/course/te/802/science08/astronomy/SSIOG%20IMAGES/milky_way.jpg