kelvin (K)

Zero K is absolute zero; ice melts at 273 K (0° C, 32° F); water boils at 373 K ( 100° C, 212° F).

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Kepler, Johannes 1571-1630

German astronomer and mathematician. Considered a founder of modern astronomy, he formulated the famous three laws of planetary motion. They comprise a quantitative formulation of Copernicus's theory that the planets revolve around the Sun.

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kilogram (kg)

One kilogram is equivalent to 1,000 grams or 2.2 pounds; the mass of a liter of water.

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kilometer (km)

One kilometer is equivalent to 1,000 meters or 0.62 miles.

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Kowal, Charles T. 1940-

American astronomer. Kowal discovered Leda and comet-like object Chiron.

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Kuiper, Gerard, 1905-1973

Dutch-born American astronomer. Kuiper is best known for his study of the surface of the Moon. He discovered Miranda and Nereid and found an atmosphere on Titan.