Impact angle
Impact angle is the angle between an impactor's path and the ground; the most likely angle is 45 degrees.
The impact angle describes how steeply an asteroid or comet hits the ground, measured from the horizontal. A vertical impact is 90 degrees and a grazing impact close to 0 degrees.
Perhaps surprisingly, the most common angle is 45 degrees. Calculations first made by the American physicist Grove Karl Gilbert in the 1890s and later refined show that impacts at about 45 degrees are more likely than vertical or grazing ones, because objects come from all directions in space. Vertical and very shallow impacts are both rare.
Angle matters because it affects how much energy is transferred to the ground and where ejecta goes. A shallow impact sends more material forward and may produce less melting. Studies of the Chicxulub crater, linked to the extinction of the dinosaurs, suggest the impactor struck at a steep angle of roughly 45 to 60 degrees, which made it especially effective at throwing climate-changing gases into the atmosphere.
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