William Herschel was a musician and composer of church
music, many concertos, and twenty-four symphonies.
Speculum is an alloy of about two-thirds copper and
one-third tin. Isaac Newton made a 1.3-inch speculum mirror for
the first successful reflecting telescope in 1668.
An altazimuth mount lets the telescope move on two
perpendicular axes, one vertical and the other horizontal.
Herschel discovered two moons of Uranus, Titania and Oberon,
and two moons of Saturn, Mimas and Enceladus. William’s son
John named these moons after William died.
Although he did not discover the first asteroid, Herschel
coin the term “asteroid” from the Greek for
Herschel measured the tilt of Mars and discovered its ice
caps. “He was the first to realize that the solar system is
moving through space, and he determined the approximate direction
of that movement. He also studied the structure of the Milky Way
and concluded that it was in the shape of a disk.”
Herschel discovered the infrared spectrum in sunlight.
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