Kuiper, Gerard Peter (1905-1973)

Dutch-born US astronomer who made extensive studies of the Solar System. His discoveries included the atmosphere of the planet Mars and that of Titan, the largest moon of the planet Saturn. In 1951 he proposed the existence of the Kuiper belt, a ring of small bodies orbiting the Sun beyond the outermost planet.

Kuiper was adviser to many NASA exploratory missions, and pioneered the use of telescopes on high-flying aircraft. The Kuiper Airborne Observatory, one such telescope, is named after him; it was permanently grounded in October 1995.

Kuiper was born in Harenkarspel and educated at the University of Leiden, emigrating to the USA 1933. He joined the staff of the Yerkes Observatory, Williams Bay, Wisconsin, and was its director 1947-49 and 1957-60. From 1960 until his death he held a similar position at the Lunar and Planetary Laboratory at the University of Arizona.

In 1948 Kuiper correctly predicted that carbon dioxide was one of the chief constituents of the Martian atmosphere. In the same year he discovered the fifth moon of Uranus, which he called Miranda, and in 1949 he discovered the second moon of Neptune, Nereid. Kuiper's spectroscopic studies of Uranus and Neptune led to the discovery of features subsequently named Kuiper bands, which indicate the presence of methane.