From Wikipedia, the free encyclopedia

Tom Gehrels (born Feb 21, 1925, Haarlemmermeer, the Netherlands) is an American astronomer, Professor Planetary Sciences, and Astronomer at the University of Arizona, Tucson.

Gehrels pioneered the first photometric system of asteroids in the 50s, and wavelength dependence of polarization of stars and planets in the 60s, each resulting in an extended sequence of papers in the Astronomical Journal.

He has discovered, jointly with the husband and wife team of Cornelis Johannes van Houten and Ingrid van Houten-Groeneveld, over 4000 asteroids, including Apollo asteroids, Amor asteroids, as well as dozens of Trojan asteroids. That was done in a sky survey using the 48-inch Schmidt telescope at Palomar Observatory and shipping the plates to the two Dutch astronomers at Leiden Observatory, who analyzed them for new asteroids. The trio are jointly credited with several thousand discoveries. Gehrels also has discovered a number of comets.

He was Principal Investigator for the Imaging Photopolarimeter experiment on the Pioneer 10 and Pioneer 11 first flybys of Jupiter and Saturn in the 70s.

Gehrels initiated the Space Science Series of textbooks, which are at the most advanced level, was General Editor for the first 30 volumes of the University of Arizona Press, and set the style by participating in the editing of six of them. He also initiated the Spacewatch program and was its Principal Investigator (PI) for electronic surveying to obtain statistics of asteroids and comets, including near-Earth asteroids. Bob McMillan was co-investigator and manager, and became the PI in 1997.

Gehrels teaches an undergraduate course for non-science majors in Tucson in the Fall, and lectures a brief version of that in the Spring at the Physical Research Laboratory in Ahmedabad, India, where he is a lifetime Fellow. That is in a UN Course for graduate students from countries as Uzbekistan and North Korea, for example.

Presently, his research is on universal evolution, which is woven in as the guiding thread through these courses. He was the named winner of the 2007 Harold Masursky Award for his outstanding service to planetary science.

During World War II Gehrels was, as a teenager, active in the Dutch Resistance. After he escaped to England, he was sent back by parachute as an organizer for Special Operations Executive SOE.

Gehrels was requested by the Journal Nature to write a review on a book regarding Wernher von Braun, in which he quotes inmates of concentration camp Dora. He has therefore charged that von Braun was there regularly and much in charge, and that von Braun bears greater responsibility and guilt than his official biography would imply^[1]. Towards the end of the book review it reads: Von Braun needs no phony defense, for he was a great man in his own scientific specialization... What is needed is a more sophisticated historical perspective....

• Special airborne services in Europe and Far East, 1944-1948.
• B.S. astronomy and physics, Leiden University 1951.
• Ph.D. astronomy and astrophysics, Univ. of Chicago, 1956.
• Planetary sciences and astronomy, Univ. of Arizona, 1961-present.

• Physical Studies of Minor Planets, edited by Tom Gehrels (1971), NASA SP-267
• Planets Stars and Nebulae Studied With Photopolarimetry, edited by Tom Gehrels (1974), ISBN 0-81650-428-8
• Jupiter: Studies of the Interior, Atmosphere, Magnetosphere, and Satellites, edited by Tom Gehrels and Mildred Shapley Matthews (1976), ISBN 0-81650-530-6
• Protostars & Planets: Studies of Star Formation and of the Origin of the Solar System, edited by Tom Gehrels and Mildred Shapley Matthews (1978), ISBN 0-81650-674-4
• Asteroids, edited by Tom Gehrels and Mildred Shapley Matthews (1979), ISBN 0-81650-695-7
• Saturn, edited by Tom Gehrels and Mildred Shapley Matthews (1984), ISBN 0-81650-829-1
• Asteroids II, edited by Richard P. Binzel, Tom Gehrels, and Mildred Shapely Matthews (1989), ISBN 0-81651-123-3
• Hazards Due to Comets and Asteroids, edited by Tom Gehrels, Mildred Shapley Matthews, and A. M. Schumann (1994), ISBN 0-81651-505-0
• On the Glassy Sea, in Search of a Worldview, Tom Gehrels (2007, originally published in 1988), ISBN 1-4196-8247-4
• Survival Through Evolution: From Multiverse to Modern Society, Tom Gehrels (2007), ISBN 1-41967-055-7

1. ^ Of Truth and Consequences, Tom Gehrels (1994). Nature 372, 511-512

• Gehrels - university page