* Astronomy

Expand
Location near: 3.7°N, 348.2°W

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a small impact crater with a "butterfly" ejecta pattern.

The butterfly pattern results from an oblique impact.
Not all oblique impacts result in an elliptical crater, but they can result in a non-radial pattern of ejecta distribution.
The two-toned nature of the ejecta - with dark material near the crater and brighter material further away - might indicate the nature of subsurface materials. Below the surface, there may be a layer of lighter-toned material, underlain by a layer of darker material.
The impact throws these materials out in a pattern that reflects the nature of the underlying layers.