Tuesday, 10 March 2015

Assignment 4: The changing Pluto.



Pluto was once thought to be one of the nine planets of our solar system, however it was reclassified as a dwarf planet in 2006. Pluto is the furthest planet from the sun and is unique from the other outer planets. Pluto is composed of primarily rock with an outer layer of frozen water. This is vastly different compared to the gaseous composition of the outer planets in the solar system. Pluto is known as one of the largest celestial object in the Kuiper Belt, amongst its vast population of comets.

In 1905, Percival Lowell, an astronomer observed deviations between the orbits of Neptune and Uranus hence predicting the existence of a ninth planet. He later died without ever finding the planet. Pluto was discovered by Clyde William Tombaugh in 1930 at the Lowell Observatory in Flagstaff, Arizona. Tombaugh was born on February 4, 1906 in Illinois. He was not from a wealthy family and thus was not financially capable to attend college, although, he did graduate High School in 1925. Throughout his early life he had an interest towards astronomy, thus using his uncle’s telescope, he would observe the night sky. Later in 1926, he constructed a telescope by following the guidelines provided in an article published in the magazine Popular Astronomy. This fascination led him to construct two more telescopes and using these, Tombaugh was able to make drawings of Mars and Jupiter. He later sent these drawings to the Lowell Observatory in 1929. His intention was to receive feedback about his work but rather he was offered a job at the observatory. This job required him to photograph the night sky using a 13 inch telescope and to look for any differences in the sky by comparing the images. The intention of his work was to locate Planet X. It was on February 18, 1930, Tombaugh discovered the ninth planet, later named Pluto. It was declared as the ninth planet on March 18, 1930. After this discovery, he was able to pursue an education with a scholarship to earn an undergraduate degree at the University of Kansas. Later he continued his education and received a Master’s degree in astronomy in 1939. Meanwhile, he continued working at the Lowell Observatory and made additional contributions to astronomy by discovering more than thirty thousand objects in the sky. Additionally, he had an interest for the planet Mars and provided in depth observations about its surface and provided an explanation for the presence of craters on Mars. During World War II, he was hired by the Navy to teach navigation at Arizona State College until the end of War. Following the War, he obtained another job at the University of California as a visiting assistant professor because Lowell laboratory wasn’t able to employ him. Clyde William Tombaugh later died in 1997, and his ashes are to be sent on a probe to Pluto in 2015.

The existence of another planet after Neptune was first proposed by Percival Lowell. Lowell founded the Lowell Observatory, which was used by Tombaugh to find Pluto. Lowell first noticed that Neptune and Uranus orbits were being affected by an external force from beyond them. These observations led him to believe of another planet that was yet to be discovered. He dedicated his life to finding this mysterious planet and spent countless hours predicting the location using various mathematical calculations. Lowell was never able to find this planet. Tombaugh was later set with the task of finding the planet. He had used a blink comparator to find Pluto. A blink comparator enables one to observe two pictures simultaneously by switching between them quickly this allows the user to notice any variations in the pictures. Hence able to identify any movement in celestial objects. Tombaugh was able to find Pluto using the blink comparator in 1930.
Pluto was discovered by Tombaugh by complete accident. Tombaugh was looking for the proposed planet by Lowell based on Lowell’s calculations, which were found to be completely wrong. Tombaugh was able to locate Pluto, which was miniscule compared to Lowells’ predictions. Lowell believed that Neptune and Uranus were being greatly affected by this mysterious planet, however Pluto’s gravity would have minimal impact on the other planets due to its sheer size.

The discovery of Pluto lead to a lot of controversy in the astronomical field. The sheer size of Pluto made scientists question the meaning of the word planet. This is due to the fact that Pluto is smaller the many of the moons found in our solar system. In addition, Pluto unlike the other outer planets has a rock core. In addition, the existence of more icy celestial objects beyond Pluto were proposed by Gerard Kuiper. This was discovered in 1992 and was given the name Kuiper Belt. Which now holds Pluto as one of the largest members amongst the Kuiper Belt. Due to the controversy regarding classifying Pluto as a planet, the International Astronomical Union classified Pluto as a dwarf planet. In addition, the International Astronomical Union classified any objects orbiting the sun beyond Neptune to be classified as plutoids.

Plutinos are celestial objects that orbit the sun in our solar system that are at a greater distance than Neptune. These minor planets must be further than 30 astronomical units from the sun.  Plutinos orbit 2 times for every 3 times that Neptune orbits. They were named after the dwarf planet, Pluto. Plutinos occupy a great amount of the known Kuiper belt objects.


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1 comment:

  1. *no in-text citations = plagiarism! consider this a warning*
    need more info on plutinos + discovery

    ReplyDelete