The latest images from the ESA Venus Express probe show an unusual dark vortex swirling around the planet's south pole. A similar vortex was previously observed over Venus' north pole, so the findings were not unexpected. What the scientists don't understand is how the vortexes achieve stability, and where they get their energy.

The image to the right is color enhanced, and is at a scale corresponding to 50 kilometers per pixel.

The Venus Express Probe - first expedition to that planet in over fifteen years - will continue its polar (north-south) orbit for the next year and a half. Scientists are hoping to understand how a planet so similar to Earth should have developed so differently over the past 4-1/2 billion years.