The partial circle on the left is the fraction of rotation of the
Earth needed for the comet in the middle to strike the Earth on the
right. This would be about one quarter or one fifth of 24 hours; the
manmade status of this circle leaves out the real distance of the
comet from the Earth. The thick line within the Earth implies extra
velocity adjustments right before the strike, which are not
corroborated in prior
circles.