Some 500 light-years away, a giant gas planet named WASP-127b is caught in a cosmic tempest. Winds howl across its equator at speeds of up to 33,000 kilometers per hour (20,000 mph) — nearly six times faster than the planet itself rotates. These supersonic jetstreams, the fastest ever measured on a planet, are so furiously strong they’re rewriting our understanding of weather beyond the Solar System.
“This is something we haven’t seen before,” said Lisa Nortmann, an astronomer at the University of Göttingen, Germany, and lead author of the study published in Astronomy & Astrophysics.
There’s more to this far-away planet. While slightly larger than Jupiter, WASP-127b has only a fraction of its mass, giving it a “puffy” nature that intrigues scientists.
A Puffy Planet with a Violent Heart
WASP-127b’s low density makes it an ideal cosmic laboratory for studying atmospheric dynamics on other worlds. The team used the CRIRES+ instrument on the European Southern Observatory’s Very Large Telescope (VLT) in Chile to analyze how starlight filters through the planet’s upper atmosphere. They detected water vapor and carbon monoxide, but what truly stunned them was the speed of the atmospheric material.
“Part of the atmosphere of this planet is moving towards us at a high velocity while another part is moving away from us at the same speed,” Nortmann explained. This “double peak” in the data revealed a supersonic jetstream racing around the equator.
For comparison, the fastest winds in our Solar System, found on Neptune, top out at a mere 1,800 kilometers per hour. WASP-127b’s winds are in a league of their own.
A Weather Map of an Alien World
The team didn’t stop at wind speeds. They also mapped temperature variations across the planet. The poles are cooler than the equator, and there’s a subtle difference between the morning and evening sides. “This shows that the planet has complex weather patterns just like Earth and other planets in our own System,” said Fei Yan, a co-author of the study and a professor at the University of Science and Technology of China.
These findings are more than just a glimpse into the chaos of an alien world. They offer clues about how heat and chemicals are redistributed in planetary atmospheres — processes that could shed light on the formation and evolution of planets, including those in our own Solar System.
Until recently, astronomers could only measure the mass and radius of exoplanets. Now, thanks to instruments like CRIRES+, they can peer into their atmospheres and even map their weather. But this is just the beginning.
The Extremely Large Telescope (yes, astronomers love to name telescopes like this), currently under construction in Chile, promises to take this research even further. With its advanced ANDES instrument, scientists will be able to study smaller, rocky planets and resolve even finer details of atmospheric dynamics. “This means we can likely expand this research to planets more like Earth,” Nortmann said.
For now, WASP-127b serves as a reminder of the wild, unpredictable forces that exist far beyond our solar system.
