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Mirrors and Lenses
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:
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Galileo Galilei
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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Space Travel
NASA
In 1958, the Congress of the United States enacted, and the President Dwight D. Eisenhower signed, the National Aeronautics and Space Administration Act (NASA). The act begins with a very simple statement; "An Act to provide for research into the problems of flight within and outside the Earth's atmosphere, and for other purposes."
The Cold War between the United States and (what was) the Soviet Union was in full swing. With the passing and signing of the act that established NASA, what has come to be known as the "space race" was kicked off. The Soviet Union had launched Sputnik 1 and had an apparent head start in the race to space.
The United States caught up quickly. In January 1958, Explorer 1 (America's first earth satellite) was launched.
Then NASA launched human space flight initiatives with Mercury's single astronaut program (flights during 1961-1963) to determine if a human could survive in space.
The Project Gemini (flights during 1965-1966) with two astronauts to was used to practice space operations, like rendezvousing and docking spacecraft and extravehicular activity (EVA or space walks).
This was followed with Project Apollo (flights during 1968-1972) to explore the Moon. Since then NASA has conducted robotic missions to the Moon (Ranger, Surveyor, and Lunar Orbiter); Venus (Pioneer Venus), Mars (Mariner 4, Viking 1 and 2), and the outer planets (Pioneer 10 and 11, Voyager 1 and 2).
NASA has had its problems over the years. The space shuttle Challenger blew up on January 28, 1986, killing seven astronauts. The space program was grounded for two years. Another tragedy happened on February 1, 2003, when the space shuttle Columbia disintegrated on re-entry. All seven people on board were killed instantly.
Space travel is not without its dangers, but space in the next great frontier for mankind to conquer. You can be sure that the space program and NASA will continue into the foreseeable future.
Related Topics: Basic Astronomy Quiz,
Ham the Chimp, Mirrors and Lenses
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