Many examples of such chains are thought to have been formed by the impact of a body that was broken up by tidal forces into a string of smaller objects following roughly the same orbit. An example of such a tidally disrupted body that was observed prior to its impact on Jupiter is Comet Shoemaker-Levy 9. During the Voyager observations of the Jupiter system, planetary scientists identified 13 crater chains on Callisto and three on Ganymede (except those formed by secondary craters). Later some of these chains turned out to be secondary or tectonic features, but some other chains were discovered. As of 1996, 8 primary chains on Callisto and 3 on Ganymede were confirmed.
Crater chains seen on the Moon often radiate from larger craters, and in such cases are thought to be either caused by secondary impacts of the larger crater's ejecta or by volcanic venting activity along a rift.
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^Schenk P. M.; Asphaug E.; McKinnon W. B.; Melosh H. J.; Weissman P. R. (June 1996). "Cometary Nuclei and Tidal Disruption: The Geologic Record of Crater Chains on Callisto and Ganymede" (PDF). Icarus. 21 (2): 249–274. Bibcode:1996Icar..121..249S. doi:10.1006/icar.1996.0084.
^H. Masursky; G. W. Colton; F. El-Baz, eds. (1978). "Chapter 5: Craters". Apollo over the Moon: a view from orbit. NASA SP-362. NASA. Archived from the original on 2013-04-19.