One of the peculiarities of Venus’s surface is numerous large circular or elliptical structures named coronae. These are poorly understood, but may reflect sites where magma from the hot interior is rising towards the surface.

This radar image is 420 km across, and shows a medium-size corona called Sacajawea. It is partially surrounded by fractures paralleling its shape, and its centre appears to have sagged. The rugged terrain near the northern edge of the image is a remnant of the oldest surviving surface of Venus, now largely buried by dark (smooth) lava flows.

A 300 km wide radar image showing the near-circular structure of Aine corona, picked out by a concentric fracture pattern. Note the ‘pancake dome’ just beyond its northern edge and a smaller version within the corona. The branching canyon system in the northeast may have been eroded by lava flowing along fracture systems.

A composite perspective view made by draping a radar image onto a computer model of topography, showing the 100 km diameter structure known as Idem-Kuva corona, revealing that in this case the centre is uplifted and is surrounded by a concentric depression.

Continue your journey across the surface of Venus:

Terrain: An introduction
Volcanoes
Lava flows
Craters
Fractures
Mountain belts

Please note these pages include a number of large images which may take a few seconds to load if you have a slow connection to the internet.

All images: NASA-JPL Photojournal

Content last updated: 21/03/2006

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