Columbia Encyclopedia

Search results

500 results found

gamma-ray astronomy

(Encyclopedia)gamma-ray astronomy, study of astronomical objects by analysis of the most energetic electromagnetic radiation they emit. Gamma rays are shorter in wavelength and hence more energetic than X rays (see...

X-ray astronomy

(Encyclopedia)X-ray astronomy, study of celestial objects by means of the X rays they emit, in the wavelength range from 0.01 to 10 nanometers. X-ray astronomy dates to 1949 with the discovery that the sun emits X ...

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...

Hades

(Encyclopedia)Hades hāˈdēz [key], in Greek and Roman religion and mythology. 1 The ruler of the underworld: see Pluto. 2 The world of the dead, ruled by Pluto and Persephone, located either underground or in the...

Saturn, in Roman religion and mythology

(Encyclopedia)Saturn, in Roman religion and mythology, god of harvests, later identified with the Greek Kronos. Little is known of the origins of his cult. His reign was regarded as the Golden Age. He was the husba...

Pickering, William Henry

(Encyclopedia)Pickering, William Henry, 1858–1938, American astronomer, b. Boston, grad. Massachusetts Institute of Technology (B.S., 1879). He taught at the Massachusetts Institute of Technology (1880–87) and ...

Persephone

(Encyclopedia)Persephone prōsûrˈpənē [key], in Greek and Roman religion and mythology, goddess of fertility and queen of the underworld. She was the daughter of Zeus and Demeter. When she was still a beautiful...

Tombaugh, Clyde William

(Encyclopedia)Tombaugh, Clyde William tŏmˈbô [key], 1906–97, American astronomer, b. Streator, Ill. Although lacking formal training or a college degree, he was hired in 1929 as an assistant by the Lowell Obse...

In

(Encyclopedia)In, symbol for the element indium. ...

Lowell Observatory

(Encyclopedia)Lowell Observatory, astronomical observatory located in Flagstaff, Ariz.; it was founded in 1894 by Percival Lowell, the American astronomer who popularized the idea that Mars might support intelligen...