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Stefania (crater)
Encyclopedia
Stephania is a crater
on Venus
in the northern Sedna Planitia
. With a diameter of 11 kilometres (6.8 mi) 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 3 kilometres (1.9 mi) in diameter, and even craters smaller than 25 kilometres (15.5 mi) 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
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.
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
on Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...
in the northern Sedna Planitia
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....
. With a diameter of 11 kilometres (6.8 mi) 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 3 kilometres (1.9 mi) in diameter, and even craters smaller than 25 kilometres (15.5 mi) 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 crater
Secondary craters are impact craters formed by the ejecta that was thrown out of a larger crater. They sometimes form radial crater chains.-External links:*...
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.