Neptune is the Solar System’s most remote planet. What drives its extraordinary winds?

The winds on Jupiter average about 400 kilometers per hour, with the fastest streaming around the Great Red Spot at 635 kilometers per hour. On Saturn, wind speeds up to 1800 kilometers per hour have been clocked by the orbiting Cassini spacecraft, while Hubble Space Telescope observations of Uranus show the cloud bands blowing at 900 kilometers per hour. On Neptune, a place so cold that nitrogen, oxygen, and argon could freeze into solids, winds around the Great Dark Spot are moving at almost 2000 kilometers per hour.

According to conventional theories, planetary winds are caused by convention: cold air flowing into regions of warm air. That convection is thought to be from solar energy selectively heating different atmospheric regions, causing gases to rise and fall. Why is it that the planets receiving the least solar energy experience the greatest convection? On Neptune, for instance, the Sun is 900 times dimmer than seen on Earth, yet the average winds on our planet are a mere 56 kilometers per hour. The fastest wind was recorded on December 17, 1997: 378 kilometers per hour on the island of Guam.

It seems illogical that the initiator of Neptune’s wind speed is presumed to be the Sun heating a gas giant planet 49,500 kilometers in diameter from 4.486 X 10^6 kilometers away. Presumption would seem to require something more like amazement that such a tiny pinpoint of light in space—little more than a bright star from Neptune’s perspective—could stimulate this large effect..................