A rainbow-like feature known as a “glory” has been seen by ESA’s Venus Express orbiter in the atmosphere of our nearest neighbor – the first time one has been fully imaged on another planet.
Rainbows and glories occur when sunlight shines on cloud droplets – water particles in the case of Earth. While rainbows arch across wide swathes of the sky, glories are typically much smaller and comprise a series of colored concentric rings centered on a bright core.
The atmosphere of Venus is thought to contain droplets rich in sulphuric acid. The glory in the images here was seen at the Venus cloud tops, 70 km above the planet’s surface, on 24 July 2011. It is 1200 km wide as seen from the spacecraft, 6000 km away.
Even more interesting, the color variations are not at all what would be expected from clouds containing sulphuric acid and water alone, suggesting that some other kind of chemical interplay is probably at play here as well.
Venus gets shorted sometimes in relation to Mars due to its brutally inhospitable surface, but there are some intriguing possibilities and things to learn from our comely green neighbor.
Via European Space Agency for the full article and additional imagery.