Tom Gehrels

Tom Gehrels (1925 – 2011), was an American astronomer, Professor Planetary Sciences, and Astronomer at the University of Arizona, Tucson. With co-workers, he discovered over 4,000 asteroids, including Apollo asteroids, Amor asteroids, as well as dozens of Trojan asteroids. Gehrels also discovered a number of comets. In an interview, Gehrels was asked what he would do if an asteroid hit the Earth. He said, "Go out there and have a look, of course."
In the 1970s, Gehrels was in charge of the Imaging Photopolarimeter experiment on the Pioneer 10 and Pioneer 11 satellites which explored the planets, Jupiter and Saturn.
Gehrels edited a number of space science textbooks. One of his sons, Neil Gehrels, was also an astronomer.
Gehrels was part of the Dutch Resistance in World War II. In 1994, he argued that German rocket scientist Wernher von Braun had been involved in Nazi concentration camps during that war.