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Basic Astronomy Quiz
The Demotion of Pluto
The year was 1930. An astronomer, Clyde Tombaugh, was just 24 years old. He was studying the night sky at Lowell Observatory in Arizona when he discovered what would come to be known as Pluto…the ninth planet in our solar system. On January 23, 1930, Clyde saw a dim speck moving among the stars. It was quickly hailed as not only the ninth planet in our solar system, but the first planet discovered by an American. Americans were so proud!
There were a lot of names suggested for the new planet that Tombaugh had discovered. It was his prerogative to choose the name. Suggestions flowed in from all over the world. "Pluto" was suggested by then-11-year-old Venetia Burney from Oxford, England. She wanted to name the planet after Mickey Mouse's dog (Mickey's dog Pluto debuted that same year). Tombough liked the name and chose it. Venetia still lives in England and is quoted as having said, "It has now been satisfactorily proven that the dog was named after the planet, rather than the other way round."
Problem is, Pluto is no longer a planet. It didn't change, disintegrate, or disappear from the night sky. Rather, it fell victim to what some describe as "politics."
Pluto is no longer considered a planet thanks to votes cast by only 424 astronomers (5% of the membership) on the very last day of the meeting of the International Astronomical Union (IAU) in Prague in 2006.
Mike Brown, an astronomer from CalTech (and another American), recently discovered another Pluto-sized object that will not be called a planet either, under the new guidelines.
Many of those who are in a position to know say that the decision will not stand and that textbooks should not be rewritten just yet. The vote has been taken, but the debate isn't over.
See Also:
Christopher Wren - Wikipedia, the free encyclopedia
Asteroids, Comets and Meteors
The Planet Uranus
William Herschel accidentally discovered the planet Uranus in 1781. Uranus had been seen many times before, but it had always been dismissed as a star.
Uranus is made up mostly of hydrogen and helium like Jupiter and Saturn, but it has higher concentrations of heavy elements. Our closest look at Uranus was given to us by Voyager 2 in 1986.
Uranus is one of the four "Giant Gas Planets" (the other three are Jupiter, Saturn, and Neptune). The rings around Uranus are made up of rock, rather than ice like those of Saturn. We do know that there are five large moons and at least 10 smaller moons. The rotational period of Uranus is a little over 17 hours, and its orbital period is 84 years.
Uranus appears to be a giant blue featureless ball. Voyager 2 got relatively close to Uranus and could not pick up any distinguishable features. It is believed that the upper atmosphere of Uranus has a high-level petrochemical haze that probably obscures features lower in the atmosphere. The blue color is caused by methane gas in the atmosphere. Methane gas absorbs red and orange light, which leaves more blue light.
Voyager 2 confirmed that Uranus has a magnetic field. The field is more than 50 times stronger than that of Earth and is tilted about 60 degrees.
The latest scientific data suggests that Uranus is surrounded by at least five rings. The brightest ring is called the Epsilon ring. Voyager 2 located two small shepherd moons for it, one just inside and one just outside. These two shepherd moons have been named Ophelia and Cordelia.
The most interesting moon that circles Uranus is Miranda. Miranda isn't very big, but it has some very interesting geological features. |
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More articles:
Earth and stars to scale.
Basic Astronomy QUIZ: Chapter 21
The Nine Planets Solar System Tour
Mirrors & Lenses
Science as a Way of Knowing:
Galaxies
Sir Christopher Wren
Sir Christopher Wren once said, "In things to be seen at once, much variety makes confusion, another vice of beauty. In things that are not seen at once, and have no respect one to another, great variety is commendable, provided this variety transgress not the rules of optics and
geometry." For those of you who do not know, Christopher Wren was an English architect and mathematician who became Savilian Professor of Astronomy at Oxford in 1661. He is most famous for the buildings that he designed after the Great Fire of London.
Wren was interested in many things, and over his lifetime, he made many contributions to scientific knowledge and in many different ways. For example, he constructed a transparent beehive for the purpose of scientific observation; he studied the moon and experimented on terrestrial magnetism; and he also performed the first successful injection of a substance into a dog's bloodstream.
Along with Sir Paul Neile, Wren constructed a 35-foot telescope. During this timeframe, Wren also studied and improved the microscope and the telescope.
Wren was fascinated by the planet, Saturn. He began his observations of Saturn about 1652 with the intention of explaining the rings. Wren developed a hypothesis which he wrote in De Corpore Saturni. Before his work could be published however, Christian Huygens (a Dutch astronomer) presented his theory of the rings of Saturn. Wren immediately recognized the fact that Huygens' was a better hypothesis than his own, so De Corpore Saturni was never published.
Wren constructed a beautifully detailed model of the moon and gave it to the king. Although Sir Christopher Wren eventually turned his attention to architecture, he remained fascinated by astronomy all of his life.
Related Topics: The Planet Mars,
The Hubble Space Telescope, Our Sun
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