Survey for bright Mars-crossing asteroids

Eugene Merle Shoemaker; Carolyn S. Shoemaker; E. F. Helin; S. J. Bus; R. F. Wolfe

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Survey for bright Mars-crossing asteroids

Eugene Merle Shoemaker·Carolyn S. Shoemaker·E. F. Helin·S. J. Bus·R. F. Wolfe

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Abstract

A new method of search for relatively bright Mars-crossing asteroids with the Palomar 46-cm Schmidt camera was initiated in 1980. Selected fields photographed with the 46-cm Schmidt were systematically reduced for all asteroids detected on the films. The 46-cm Schmidt fields have an effective diameter of 8 3/4 degrees. Kodak 11a-D film was exposed with a yellow plexiglass filter. The films were scanned with a specially designed stereomicroscope that permits recognition of asteroids by stereopsis. Stereoscopic pairs of films were exposed with a time separation of 30 minutes; over this interval the parallax in position relative to the background stars allows easy recognition of asteroids at distances ranging from near the Earth through the main belt. Optimum exposure for each film was found to be 10 minutes on the f/2 Schmidt.

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Eugene Merle Shoemaker, Carolyn S. Shoemaker, E. F. Helin, S. J. Bus, R. F. Wolfe. 1981. Survey for bright Mars-crossing asteroids. https://pubs.usgs.gov/publication/70226967

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