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Astronomy

explanatory Essay
1026 words
1026 words
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One thing us as humans have never been able to fully understand is astronomy. Always having an unexplained mystery, astronomy also has served as a way to keep time and predict the future. The word “astronomy” is defined as the study of heavenly bodies, meaning anything in the sky such as stars, galaxies, comets, planets, nebulae, and so on. Many people, if not everyone, is amazed by the night sky on a clear, moonless night.

Astronomy dates back to ancient times when peoples such as the Babylonians, Egyptians, and Chinese kept written records of astronomical events and occurrences. Today’s seven day week originates from the Babylonians’ seven important bodies in the night sky: the Sun, Moon, Mars, Mercury, Jupiter, Venus, and Saturn. The ancient Egyptians used the stars to align their pyramids and many of their corridors in almost perfect north-south or east-west directions. The Chinese were experts at predicting solar eclipses. They believed that a solar eclipse was a dangerous warning. Chinese astronomers were executed if they failed to predict an eclipse.

Over the years there have been many more important figures in astronomy. One extraordinary astronomer was Galileo Galilei who invented the first refractor telescope in which light is bent to enlarge an image of the sky (“Galileo Project”). The next great astronomer to follow him was Isaac Newton. Newton had made a great amount of contributions to astronomy during his life. He further proved that the Earth was not the center of the universe and he also invented the Newtonian reflector telescope which is still used today in observatories. Also, he discovered that light could be split into a visible spectrum of colors. Spectral colors from stars would later be used to determine their size, temperature, chemical composition, and even the direction the star is moving.

Today, professional astronomers play a very different role than hundreds of years ago. Surprisingly, astronomers today spend minimal time at the telescope gazing at the night sky. Operating planetariums, teaching astronomy classes, or operating and maintaining an observatory are some of the things astronomers today do.

Along with professional astronomers are amateur astronomers who only observe the heavens for personal satisfaction and enjoyment. I myself am an amateur astronomer an...

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...enith (straight overhead position). Two galaxies which are believed to revolve around our own are the Small and Large Magellanic Clouds. Only visible from the Southern Hemisphere, Magellan, the famous European explorer, was the first to describe these galaxies.

Even though we know a great amount more than the astronomers in the past, there is still an even larger amount we do not know about the universe to this day. Even our own solar system contains many questions yet to be answered. Some of these include the possibility of a planet beyond Pluto (Planet X), the means by which the system was created, and even the possibility of a sister star to the Sun named Nemesis. Another astronomical mystery is the creation of the universe. In time, many questions will be answered but some will always remain. Astronomy is something that will never be completely understood.

Works Cited:

Goldsmith, Donald. The Astronomers. New York: St. Martin’s Press,
1991.

Fradin, Dennis P. Astronomy. Chicago: Children’s Press, 1987.

“The Galileo Project”. in History of Astronomy. [collection of sites]
(rev. Dec. 2002; accessed 6 Jan, 2002); available from http://www.cv.nrao.edu/fits/www/yp_history.html

In this essay, the author

  • Defines astronomy as the study of heavenly bodies, meaning anything in the sky. many people, if not everyone, are amazed by the night sky on a clear, moonless night
  • Explains that ancient peoples such as the babylonians, egyptians, and chinese kept written records of astronomical events and occurrences.
  • Describes the contributions of galileo and isaac newton to astronomy, including the invention of the first refractor telescope.
  • Explains that professional astronomers today spend minimal time gazing at the night sky. they also observe the heavens for personal satisfaction and enjoyment.
  • Explains that radio, x-ray, ultraviolet, or infrared instruments are used to observe celestial bodies.
  • Explains that our own solar system today is thought to have formed from a large, single cloud of dust and gas.
  • Explains that the milky way contains single stars and clusters of stars, which are held together by their own gravity.
  • Explains that the night sky is shared with other galaxies than our milky way. the andromeda galaxy is one of the closest to our own.
  • Opines that even though we know a great deal more than the astronomers in the past, there is still an even larger amount we do not know about the universe to this day.
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