, an arachnoid
is a large structure of unknown origin, and they have been found only on the surface of the planet Venus
. Arachnoids get their name from their resemblance to spider webs
. They appear as concentric
ovals surrounded by a complex network of fractures
, and can span 200 kilometers. Over thirty arachnoids have been identified on Venus, so far. The arachnoid might be a strange relative to the volcano
, but possibly different arachnoids are formed by different processes.
Original entry was from the Astronomy Picture of the Day;
This article incorporates text from a public-domain NASA website.