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The Demotion of Pluto
The Hubble Space Telescope
The Hubble Space Telescope is a wonder of engineering and ingenuity. The idea for building a telescope in space that could see far beyond our own solar system was conceived in 1962 by the National Academy of Sciences in the United States. It wasn't until 1977 that the Congress of the United States finally voted to actually fund the project.
The Hubble telescope is named for Edwin P. Hubble. Hubble was a trailblazing astronomer who was born in 1889 and died in 1953.
The Hubble telescope has given astronomers unprecedented access to views of deep space. It has actually revolutionized the science of astronomy in many ways. The Hubble Telescope can "see" far beyond our own solar system and beyond our own galaxy into deep space, where fledgling galaxies are only just beginning to form.
The Hubble telescope wasn't launched until 1990 even though it was originally scheduled to launch in 1983. The launch experienced many delays, the most notable of which was the space shuttle Challenger disaster in 1986. The Hubble telescope was launched into space on April 25, 1990, and was sending pictures back to earth in a matter of days -- but the pictures were out of focus. The problem was found to be a flaw in the giant mirror -- it was too flat on one edge by 1/50th the width of a single human hair.
In 1993, the problem with the Hubble was resolved when the space shuttle Endeavor captured the Hubble Space Telescope and added a camera to correct problems with the telescope's primary mirror.
There have been other problems with the Hubble over the years, but it is still one of the wonders of the world and is providing astronomers with information that they could never have gained access to without it.
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Astronomy for Kids
The Planet Neptune
Adams and Leverrier predicted the existence of the planet Neptune back in 1845. Neptune is very difficult to observe from the earth because of (1) the distance, and (2) the earth's atmosphere. The closest and best look that we have had at Neptune was provided by the Voyager 2 flyby in 1989.
Neptune is the most distant planet from the sun. It was once believed that Pluto was a planet Pluto beyond Neptune, but astronomers have declared that Pluto is not a planet but one of many dwarf planets in our solar system.
Neptune has a diameter that is about four times larger than earths. Computer models suggest that Neptune has a rocky core that comprises about 15 earth masses at the center, but there is no confirmation of this theory. Neptune has a rotation period of about 16 hours. Neptune has an internal heat source, and it produces about 2.7 times more heat than it absorbs.
Strong winds, bright, high-altitude clouds, and two large dark spots attributed to long-lived giant storm systems were reveled by the 1989 Voyager flyby. Wind speeds are as high as 739 miles per hour. The larger of the two dark spots that Voyager reveals is called the "Great Dark Spot."
Neptune's rings were first detected from Earth in 1983, but no real study could be conducted at that time. It wasn't until the data supplied by the Voyager 2 flyby was available that any determination about the rings could be disseminated. There are two bright rings and two fainter rings. The rings rotate in the same direction as Neptune, and they are all close to the equator.
Triton and Nereid are the two large moons of Neptune and are visible from Earth. Voyager 2 discovered six more moons, and one of them is actually larger than Nereid; but it is difficult to see because it orbits so close to Neptune. |
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Christopher Wren - Wikipedia, the free encyclopedia
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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: History of Astronomy,
Test Your Astronomy Knowledge, Sir Christopher Wren
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