About
a thousand impact craters have been identified on Venus, the largest being
280 km in diameter. Because the dense atmosphere prevents small impactors
reaching the surface with sufficient speed to form craters, the smallest
impact craters on Venus are about 3 km across. Many of these are poorly
formed or occur as overlapping clusters, suggesting the impactor broke up
in the atmosphere shortly before impact. However, from 30 km diamter upwards
each crater is virtually a work of art, with a central peak, sharp rim and
a surrounding blanket of rough ejecta with a lobate edge characteristic
of ejecta flow in a dense atmosphere. |
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Two
such craters appear in the images above. The radar-bright halo beyond the
even brighter ejecta blanket surrounding the crater Eudocia in the upper
left is more finely dispersed ejecta. |
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