Little Bits of History

Enceladus

Posted in History by patriciahysell on August 28, 2012

William Herschel

August 28, 1789: William Herschel discovered Enceladus. It is the sixth largest moon of Saturn and was named for a mythological giant. Little was known of this moon until the two Voyager spacecraft passed near it in the early 1980s. The diameter is about 310 miles (our own moon is about 1,080 miles) and it is about 1/10 the size of Saturn’s largest moon, Titan. There is water ice on the surface, making it particularly good at reflecting the sun’s light. The Voyager’s passing showed that the moon is both covered in craters from old impacts but also shows signs of tectonically deformed terrain. In 2005, Cassini showed the surface in greater detail and led scientists to determine that the moon is still geologically active.

Sir Frederick William Herschel was born in Germany on November 15, 1738. He was a musician and followed his father into the Military Band of Hanover. However, he emigrated to England when he was 19. He is known as a British astronomer and technical expert as well as a musician. He not only studied the night skies but also composed 24 symphonies. It was William’s love of music that led him to study mathematics and lenses. With this knowledge, his interest in astronomy was piqued. He met Nevil Maskelyne, an English Astronomer Royal and became even more enchanted.

William began to build his own reflecting telescopes and studied stars that were proximal in the night sky. By measuring small changes he hoped to gain a better understanding of the true position of the stars. He used a 7-foot focal length, 6.2-inch aperture telescope of his own manufacture and began a systematic search of the sky from his back yard. He found many double and multiple stars and reported to the Royal Society. His discoveries were cataloged and he continued to search, discover, and report his findings.

In March 1781, while still searching for double stars, Herschel noticed a nonstellar disk. He thought it might be a comet. He made many more observations and finally was able to chart the object’s orbit. This helped to convince him that the object was probably planetary. He named his new planet “Georgian star” for King George III which pleased the king. However the name didn’t stick. The French were particularly loathe to use the name and referred to the body as “Herschel” instead. After much debate, the planet was finally named what we now call it – Uranus.

All human discoveries seem to be made only for the purpose of confirming more strongly the truths come from on high, and contained in the sacred writings.

The difference of the degrees in which the individuals of a great community enjoy the good things of life has been a theme of declaration and discontent in all ages.

The undevout astronomer must be mad.

I have looked further into space than ever human being did before me. I have observed stars of which the light, it can be proved, must take two million years to reach the earth. – all from William Herschel

Also on this day:

First Tornado Photograph – In 1884, the first tornado photograph is made.
Sci Am – In 1845, Scientific American began publication.
Odds and Evens – In 888, the last date written in all even numbers for over a thousand years.

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