Stefania is a crater on

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

in the northern

Sedna Planitia Sedna Planitia is a large lowland area of Venus, south of Ishtar Terra. It is thought to be lava-covered and similar to a lunar mare The lunar maria (; singular: mare ) are large, dark, basaltic plains on Earth's Moon, formed by ancient aster ...

. With a diameter of it is one of the smaller craters on Venus. Because many small meteoroids disintegrate during their passage through the dense atmosphere, there is an absence of craters smaller than in diameter, and even craters smaller than are relatively scarce. The apron of ejected material suggests that the impacting body made contact with the surface from an oblique angle. Upon closer observation it is possible to delineate

secondary crater Secondary craters are impact craters formed by the ejecta that was thrown out of a larger crater. They sometimes form radial crater chains. In addition, secondary craters are often seen as clusters or rays surrounding primary craters. The study of ...

s, impact scars from blocks ejected from the primary crater. A feature associated with this and many other Venusian craters is a radar-dark halo. Since dark radar return signifies a smooth surface, it has been hypothesized that an intense shock wave removed or pulverized previously rough surface material or that a blanket of fine material was deposited during or after the impact.

References

Impact craters on Venus {{crater-stub