256 Encyclopedia of the Solar System
(a) (b)(c) (d)FIGURE 5 Large meteoroids: (a) fireball of 80-m object (estimated mass, 1 Mt) on 10 August
1972 moving left to right (see arrow) over Grand Teton National Park that apparently skipped out
of the atmosphere. (Photo by Dennis Milon.) (b) The 1-km-diameter Meteor Crater in Arizona
formed by the explosive impact of the Canyon Diablo IA octahedrite meteoroid about 50 ka ago.
(Photo by Allan E. Morton.) (c) From the videotape record of the Peekskill meteoroid during its
atmospheric traverse on 9 October 1992. During fragmentation episodes such as this one (over
Washington, D.C.), large amounts of material fell, but nothing was recovered. (d) Landing site of
Peekskill chondrite in the right rear of an automobile. (Photo by Peter Brown, University of
Western Ontario.)
of two fragments), which, after passing through her roof in
Sylacauga, Alabama in 1954 struck a recumbent woman’s
thigh, badly bruising her. The second involved a 3.6-g piece
of the Mbale (Uganda) L6 meteorite shower of 1992, which
bounced off a banana tree’s leaves and hit a boy on the head.
Chinese records from 616 to 1915 claim numerous human
and animal casualties, including many killed, by meteorite
falls. Unauthenticated reports of human injuries or human
deaths exist: One undocumented report tells of a dog being
killed by a piece of the 40-kg Nakhla meteorite shower of
1911 near Alexandria, Egypt. This, incidentally, is one of
the 32 martian meteorites. Despite the small number of
casualties to date, the probability of dying in a meteoroid
impact exceeds that of being killed in an airplane crash.
This arises because the impact of a large meteoroid, small
asteroid, or comet nucleus is capable of causing devastating
loss, indeed the total extinction of life. Such impacts seem
rare.
Meteorites may impact anywhere on Earth, and, as of
November 2004, the numbers of known falls and isolated,
non-desert-cluster finds are 1046 and 1840, respectively
(cf. Table 1). For these, it can readily be established whether
meteorite fragments found nearby are from the same mete-
oroid; however, such linkages are difficult for the numerous
meteorite pieces found clustered in hot or cold (Antarctic)
deserts since 1969. So far, starting in 1969, but mainly
since 1976, Antarctica has yielded over 31,000 fragments
[16,500 collected by JARE (Japane ́s`e Antarctic Research