The electromagnetic field of Earth affects our environment in intricate methods, and is for that reason an essential consider comprehending what keeps the world habitable for life.

Electromagnetic fields are likewise present in other Solar System worlds, like Jupiter and Saturn.

For the previous 15 years, no one prospered in straight determining the strength of the magnetic fields of exoplanets– up until now.

“This development opens a totally brand-new window on exoplanet research study,” stated Dr. Julia Seidel, an astronomer with the Laboratoire Lagrange at the Observatoire de la Côte d’Azur.

“It’s the very first time we can compare the magnetic environments of other worlds– a crucial action towards eventually comprehending which worlds can survive, keep their water, and possibly even, one day, host life as we understand it.”

The astronomers determined wind speeds on 7 tidally-locked ultra-hot Jupiters orbiting various stars.

The wind speeds in the sample varied from around 7,200 km/h to over 25,000 km/h; in contrast, the fastest winds determined on Jupiter reach speeds of around 1,500 km/h.

For their measurements, the scientists utilized information from the ESPRESSO instrument on ESO’s Very Large Telescope and from a comparable instrument on the Gemini North telescope.

When they looked at how the wind speeds differed with world temperature level, they saw an extremely appealing pattern emerge: the hotter the world, the slower the wind.

“This is completely counter instinctive due to the fact that, all things being equivalent, hot worlds have more energy to speed up the winds,” stated Professor Vivien Parmentier, likewise from the Laboratoire Lagrange at the Observatoire de la Côte d’Azur.

“Something needs to occur that decreases the wind speeds for hotter things.”

The researchers concluded that the most constant description for this secret is the existence of planet-wide electromagnetic fields, because these fields can work as a brake, decreasing the movement of charged particles in the environment.

The information for that reason enabled the authors to presume the strength of the electromagnetic field in each of the studied worlds.

They discovered them to be equivalent in strength to those discovered in our Solar System: around 4 times as strong as Saturn’s or about half the strength of Jupiter’s.

Such strong electromagnetic fields might impact more than simply the wind on these far-off worlds.

“Here in the world, we understand the appeal of the northern and southern lights, where particles from the Sun struck our electromagnetic field and are directed towards the poles, hitting gases in the environment to produce vibrant display screens of green, pink, and purple,” stated Dr. Bibiana Prinoth, an astronomer at ESO.

“On the studied exoplanets, the magnetically driven aurorae might be much more remarkable.”

The research study appears today in the journal Nature Astronomy

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J.V. Seidel et alMagnetic field strengths of hot huge exoplanets constant with Solar System worths. Nat Astronreleased online June 2, 2026; doi: 10.1038/ s41550-026-02870-1