Columbia Encyclopedia

Search results

500 results found

comet

(Encyclopedia) CE5 Comet: Whatever the direction of a comet's flight, its “tail” always points away from the sun. The tail disappears when the comet is far from the sun. comet [Gr.,=longhaired], a small cele...

Donati, Giovanni Battista

(Encyclopedia)Donati, Giovanni Battista jōvänˈnē bät-tēsˈtä dōnäˈtē [key], 1826–73, Italian astronomer, b. Pisa. Serving as director of the Florence Observatory from 1864, he was a pioneer in the spec...

meteor shower

(Encyclopedia)meteor shower, increase in the number of meteors observed in a particular part of the sky. The trails of the meteors of a meteor shower all appear to be traceable back to a single point in the sky, kn...

Olbers, Heinrich Wilhelm Matthäus

(Encyclopedia)Olbers, Heinrich Wilhelm Matthäus hīnˈrĭkh vĭlˈhĕlm mätĕˈo͝os ôlˈbərs [key], 1758–1840, German astronomer and physician. He originated (1797) the first satisfactory method for calculat...

Halley, Edmond

(Encyclopedia)Halley, Edmond hălˈē, hôˈlē [key], 1656–1742, English astronomer and mathematician. He is particularly noted as the first astronomer to predict the return of a comet and the first to point out...

Oort, Jan Hendrik

(Encyclopedia)Oort, Jan Hendrik ōrt [key], 1900–1992, Dutch astronomer. He confirmed (1927) Bertil Lindblad's theory of the Milky Way galaxy's rotation. In the 1950s he and his colleagues used radio astronomical...

Whipple, Fred Lawrence

(Encyclopedia)Whipple, Fred Lawrence, 1906–2004, American astronomer, b. Red Oak, Iowa. After graduating from the Univ. of California, Berkeley (Ph.D. 1931), he accepted a position at Harvard, where he remained f...

Halley's comet

(Encyclopedia)Halley's comet or Comet Halley hălˈē, hāˈlē [key], periodic comet named for Edmond Halley, who observed it in 1682 and identified it as the one observed in 1531 and 1607. Halley did not live to ...

tektite

(Encyclopedia)tektite tĕktīt [key], naturally occurring, silica-rich (65%–80% SiO2) glass resembling obsidian and sometimes shale, and is normally jet black to olive green. They appear as small rounded or elong...

catastrophism

(Encyclopedia)catastrophism kətăsˈtrəfĭzəm [key], in geology, the doctrine that at intervals in the earth's history all living things have been destroyed by cataclysms (e.g., floods or earthquakes) and replac...
 

Browse by Subject