Neptune Drives 2,000-kph Winds With 2.6x Energy Output and 16-Hour Rotation

1 articles · Updated · spacedaily.com · Jul 23

Voyager 2 tracked Neptune winds approaching 2,000 kilometres per hour, the fastest measured on any planet, even though sunlight there is about 900 times weaker than at Earth.
Neptune emits roughly 2.6 times the energy it receives from the Sun because internal heat flow equals about 162% of absorbed solar power, giving the atmosphere a major non-solar energy source.
A 16-hour rotation, convection, atmospheric waves and relatively weak drag appear to organize that energy into long-lived east-west jets rather than simple vertical overturning.
A 2013 Nature analysis suggested the circulation is confined to an outer weather layer no deeper than about 1,000 kilometres, though scientists still debate how the jets gain and lose momentum.
Only Voyager 2 has visited Neptune, leaving the mechanism behind its unusually efficient wind engine unresolved until a future orbiter and atmospheric probe can measure conditions below the cloud tops.