‘Bland’ Planet reveals bizarre and complex weather systems

With a reputation for being boring and bland, Uranus, which resides 2.88 billion km away from the sun, has recently revealed previously undetected large and enigmatic weather systems. By utilising different filters which increase the signal to noise ratio, recent high-resolution infra-red images taken at the Keck Observatory, Hawaii, have revealed an incredible and detailed view of Uranus’ atmosphere.

The ice giant’s blue-green atmosphere is composed of hydrogen, helium and methane, where ‘blustery’ westerly winds blow at up to 560 mph. Larry Sromovsky, from University of Wisconsin-Madison, has led the recent investigation to build up a more detailed picture of the complex atmospheric flow as these weather systems vary in shape and intensity with some remaining at fixed latitudes and others drifting towards the planet’s equator. The driving mechanism for these atmospheric processes is solar energy, however, as the intensity received is 900 times weaker than on Earth, the inferred energy dissipation is minimal and so the complexity of the weather variations is bizarre.

Smaller, subtler weather features have been unmasked, some of which have not been detected on Uranus before. These astonishing new images reveal an asymmetric view of the planetary weather system, with a swarm of small convective features observed around the North pole, which are not seen in the southern hemisphere. Just south of the equator a previously undetected scalloped band of clouds have been observed which may indicate instability of the atmosphere or wind shear effects.

Further work will aim to characterise the seasonal variation in cloud and wind trends and unravel some of the mysteries which have been exposed. Imke de Pater, from the University of, is on the lookout for a vortex at the South pole of Uranus, due to the similarity of strong convective cloud features which have also been observed on Saturn and Neptune.