Magnetic fields act as brakes and heaters in the atmosphere of ultra-hot Jupiter WASP-18 b

Star system: WASP 18 | Distance from the Sun: 400 light years

Researchers have discovered that the magnetic field of the giant planet WASP-18 b plays a dramatic role in controlling its weather. Because the planet is so close to its star, its atmosphere becomes 'ionized' or electrically charged. 

This allows the planet's magnetic field to act like a physical brake on high-altitude winds, creating a 'stop and go' effect in the atmospheric flow. This magnetic drag, combined with frictional heating, creates unusual temperature patterns, including two distinct 'hotspots' instead of one and significant temperature differences between the planet's morning and evening sides. Understanding these magnetic forces is key to figuring out the true strength of magnetic fields on alien worlds.

Scientific study

Inhomogeneous magnetic coupling in exoplanets: the stop & go of WASP-18 b's atmospheric flows (external link)