Astronomy is not just about the stars. Astronomy is about the constellations, the nine planets, the sun and the moons. The solar system is very complex and has many extraordinary objects.
There are four different types of stars: Protostars, Bright Stars, Red Giants, and White Dwarfs. Protostars are stars that are on the verge of being born. They are glowing clouds of dust and gas. Gravity pulls on every atom moving them towards the center of the cloud of dust, which causes the Protostar to collapse. Over a period of twenty million years the star begins to form and 10 million years after the pocket of gas was formed, a star is born.
The second types of stars are called Bright Stars. They are formed when the new star has completed about 35 million years of its life cycle. A star’s life cycle is a lot like a human’s life cycle, except a star’s years are in millions. When a star is about 10 million years old it is in the same stage on average as a regular human that is about twenty years old. The birth and death rate of stars is called Stellar Evolution. A Bright Star is made when nuclear fusion doubles the size of the star.
The third types of stars are called Red Giants. They are made because the outward flow of the star’s core energy stops. Gravity then steps in and squeezes the star to make it decrease in size. The core of the star’s heat increases and it starts releasing small amounts of energy, the energy holds a large amount of hydrogen gas. The star then begins to grow larger, but it does not get brighter. As a result of the sudden and fast temperature drop, the star’s color changes from blue-white to a red color. Most Red Giant stars have been found in groups called Globular Clusters. Globular Clusters are groups of up to one million stars that move through space.
The fourth type of stars are called White Dwarfs. When a White Dwarf is made the star begins cooling off. As a result of cooling, the outer gas layer spreads out. The star’s temperature drops and makes the gas layer spread out even more. Eventually, the outer layer spreads out so far that the gas layer separates from the star. Then, a Planetary Nebula (cloud of glowing atoms), moves in all directions. The star’s core isn’t giving out any more energy and is to the point of collapsing slowly. All of the matter that the star had in the beginning is still there, but it is compressed more tightly. Because it is packed so tightly the star is now as big as planet Earth. The star is still very hot. Because it is so hot it gives off a glowing white light. This star is called a “White Dwarf” because of its color. Out of the twenty stars that are closest to the Earth, two are White Dwarfs.
The next big thing about the solar system is the Planets. The nine planets play a big part in our solar system. Astronomers have been studying them for a long time but there are still many things to learn about them. The nine planets are Earth, Jupiter, Uranus, Pluto, Saturn, Neptune, Mars, Venus, and Mercury.
Mercury is also known as the planet of Hot days and Cold nights and it is the closest planet to the sun. It has the shortest year out of all the other planets, which is 88 days long and is half the size of Earth. Mercury orbits the sun at an average distance of 36 million miles. Daytime temperatures of Mercury can reach up to 800 degrees Fahrenheit. At night they can get down as low as -279 degrees Fahrenheit.
Venus, also known as Cauldron, has a yearlong period of 243 Earth days. It is the second planet away from the sun and can reach oven-like temperatures up to 475 degrees Fahrenheit, even at night. Venus is a very bright planet, totally surrounded by clouds. “It is the sunlight reflected off these clouds that makes the planet so bright” (Ridpath 24). This planet is very unique compared to the other planets because scientists discovered that Venus actually rotates backwards also.
Mars, also known as the red planet, has air so thin that a human would not be able to breathe it in. The air is made up mostly of Carbon Dioxide. Mars has an atmosphere that is so thin that someone would get sunburned if someone stayed outside for only 15 minutes. Although it is only half the size of Earth, in other ways is seems like our planet. One day on Mars is only a little over half an hour longer than ours, and it has an atmosphere with clouds like planet Earth too.
Jupiter is known as the Giant Planet and has a diameter of 88,800 miles. 16 moons orbit this gaseous planet. Jupiter has a volume that it one thousand times the volume of the Earth. It is given the name Giant Planet because it is so big. The weather of Jupiter is very stormy. The clouds keep changing in appearance as they swirl around the planet. “Only one feature, a big storm cloud called the Great Red Spot, seems to be there all the time” (Ridpath 32). Jupiter’s Great Red Spot is 15,000 miles long and 7,500 miles wide. It is big enough to swallow several Earth’s.
Saturn is known as the planet with the rings. It was found to be a lot like the planet Jupiter. Saturn’s rings have been known to be made up of millions of tiny moons. Saturn’s ring’s measure 110,000 miles from side to side and the planet it self is 74,900 miles in diameter.
In the year 1781, a German astronomer, William Herschel discovered that there must be one more planet, Uranus. Until that year, astronomers thought that there were only six planets. Uranus is a gaseous planet with green stripes. Uranus is tipped over on its axis, greater then any other planets tilt. Uranus had about 10 moons that have what looks like ice volcanoes, valleys, and racetrack-like ridges, grooves and patterns on them.
The discovery of Uranus wasn’t accidental but Neptune’s discovery was. In 1845, two young mathematicians, John Couch Adams from England and Urbain Le Verrier from France, were trying to solve a very big problem with the orbit of Uranus. The orbit of Uranus was not on the path that they had expected. They thought that an unknown planet was pulling on Uranus. That planet was Neptune, there is not a lot known about Neptune. It is four times the width of Earth and is about the same size as Uranus. Neptune’s blue-green clouds have a dark spot about the size of the Earth. This spot is thought to be a storm cloud that is similar to the Great Red Spot of Jupiter.
The last planet is Pluto. Pluto is also known as the Ice Planet and it was the last to be discovered. Pluto is the mystery planet because it is so small and it travels in darkness. Because it travels in mostly darkness, when pictures of it are taken it most often only shoes up as a small blurred dot. But with the help of technology, scientists were able to scan the pictures. When they scanned the pictures they noticed a small bump. The bump was proven to be Pluto’s only moon called Cheron.
Another great feature about the solar system is its moons. The solar system has many different moons. Except for Mercury and Venus, all of the planets have moons going around them. Jupiter has four Galilean moons, (discovered by Galileo) which are Europa, Ganymede, Callisto, and Io. Around Jupiter are about 16 total moons orbiting the planet. Saturn’s rings are thought to be made up of millions of tiny moons. These are called “Shepherding” moons. Titan is the most interesting and second to largest moon of Saturn. This moon is also the only one that has an atmosphere. Neptune has two moons, Trinton and Neried. Neried has an 800,000 mile orbit. The orbit requires a year to fully complete. The atmosphere of Neried is made up of a Nitrogen like the Earth’s atmosphere but it contains no oxygen, making it unbreathable. Uranus has 5 moons. Astronomers discovered that Oberon, Uranus’s outer most moon, has ice volcanoes on it. Another one of Uranus’s moons is Miranda. Miranda is the weirdest of all the moons, it has a huge cliff nearly 10 miles high and its surface has small racetrack-like patterns, ridges and grooves on it. As we all know, the Earth only has one moon. “The moons dominance of the night sky and the fact that it’s the only nocturnal object most people can identify, has always granted it an importance disproportionate to its modest sizeone quarter of Earth’s” (Berman, 47).
The Constellations are another great feature of our solar system. “Constellations are names for groups of stars that appear to form shapes in the sky.” (Miller, 1) There are about 2000 stars visible to the naked eye on a clear night and there are now 88 known constellations covering the whole sky. They were given their names many hundreds of years ago to help stargazers and astrologists to remember which stars were which. Astrologers use constellations to divide the sky up. Finding one constellation can help them find another because they move so slowly that they will always be found in about the same place. The earliest efforts of organizing the stars into constellations date back 6000 years ago. Many civilizations depended on the stars for direction and they became a large part of many cultures lives. The ancient Babylonians, Egyptians, Greeks, Romans and Hebrews were the first to form the constellations in the sky. Behind every constellation there is a story or tale of some sort.
The most famous constellation in called the Big Dipper. The Big Dipper is made up of a group of seven stars. Three stars form a handle and the other four form a bowl. The Big Dipper is actually not a constellation itself, but part of one called Ursa Major, or Great Bear. The Little Dipper is a smaller version of the Big Dipper which is part of the constellation Ursa Minor or Little Bear. Another famous constellation is Orion. Orion was an ancient Greek hunter and warrior. The constellation Orion shows him caring a club shield, and a sword dangling from his belt. Orion has more Bright Stars the any other constellations. The two brightest stars in it are Betelgeuse and Rigel. Betelgeuse is Orion’s shoulder and Rigel is his foot. Cassiopeia is another well-known constellation. “Cassiopeia is a group of stars, the brightest which form a large W in the northern sky.” (Miller, 10). Cassiopeia is found next to the Big Dipper and Orion. Its shape is an exact M or W, formed with the five bright stars. “The mythic Cassiopeia was an Ethiopian Queen.” (Miller 10). Constellations are probably the most interesting thing in the solar system. Most people look at them as an exciting look at the mythological part of our solar system, and others think that they are just another interesting part of the night sky.
The Universe is something no one can explain. Our Galaxy is one of the countless galaxies dotted throughout the Universe, like islands in a big ocean. Many objects in the Solar System have yet to be discovered and may never be, but it will always be there and may never change for generations to come.