6401 Roentgen and 6914 Becquerel

by Tim Hunter, Dennis Patton, David Levy, and James McGaha

Asteroids are quite common, and they are usually discovered by professional astronomers as an unexpected by-product of other research projects. If an asteroid has enough observations for a well established orbit, it is assigned a unique number. These numbers are given out in sequential fashion, signifying the asteroid's relative order of discovery. Traditionally, the discoverer of an asteroid is allowed to suggest a name for the asteroid. All asteroid names are subject to approval by the International Astronomical Union (IAU). In 1995 and 1996, the scientific world celebrated the 100th anniversary of the discovery of x-rays by Roentgen in November 1895 and radioactivity by Becquerel in March 1896. Surprisingly, we discovered that both of these famous scientists had never had an asteroid named for them. They received many honors in their lives, including the Nobel prize, but no one had thought to name an asteroid in their honor.

Therefore, we proposed to the IAU to name asteroids 6401 and 6914, respectively, in honor of Roentgen and Becquerel. Our proposal was accepted. In June 1996, the official announcement for these two new asteroid names was officially published by the IAU. 6401 Roentgen was discovered April 15, 1991, by Carolyn Shoemaker, Eugene Shoemaker, and David Levy at Palomar Mountain Observatory in the course of searching for near-Earth asteroids. 6914 Becquerel was discovered April 3, 1992, by Eugene Shoemaker, David Levy, and Henry Holt at Palomar Mountain Observatory. The citations for the asteroids was the work of DP with suggestions from TBH and DL. The citations can be paraphrased as follows:

6401 Roentgen was named to commemorate the centennial of the discovery of x-rays by the German physicist Wilhelm Conrad Roentgen in November 1895. His first image of a human being was of his wife's hand. Roentgen's research revolutionized medicine by providing a diagnostic tool still unrivaled in accuracy and simplicity. X-rays quickly became an indispensable part of patient care. Early in 1896, x-ray therapy came into being and has remained a standard treatment for cancer. This research has spread into many fields, especially astronomy, where x-rays provide a unique window on the universe. 6914 Becquerel was named for the French physicist Henri Becquerel on the centennial of his discovery of radioactivity in March 1896. Becquerel's work led to the discovery of radium, nuclear transmutation, and nuclear fission, and has had myriad applications in medicine, the sciences, and industry. Radionuclides are used in diagnosis (nuclear medicine), therapy, and research. Radiodating has revolutionized geology, archeology, anthropology, and history. Radioactivity explains how the sun and other stars maintain their intense energy output.

6401 Roentgen has an orbital period of 4.39 years, and 6914 Roentgen has an orbital period of 4.14 years. The names of these asteroids are intended to not only honor Roentgen and Becquerel, but also all those individuals since then who have built on the discoveries of Roentgen and Becquerel to increase scientific knowledge, to ease pain and suffering, and to better our lives.

<A longer version of this essay appeared in the March 1997 issue of Radiology, page 848.>