I-MAG STS Corporation
Were a statistician with too much free time to
construct a Balboa Index (named for the mythical
million to one shot boxer) of impacts by
astronomical body it would soon become clear that
Terra, with only 170 agreed craters, had taken far
fewer punches than smaller neighbors like Mars,
Luna, Mercury and Venus. True, an impactor has a
2:1 chance of hitting water on Planet Earth. Erosion
and subduction shorten crater lifetimes here.
Nevertheless, as pointed out in the slideshow, our
planet would seem to be about 80 Balboas (an impact
leaving a crater greater than 150 kilometers in
diameter - like Chicxulubs) short. Some of the
potential craters we identify might be just random
shapes, very large slope collapses or immense glacial
moraines.