Astronomers have uncovered one of the most extraordinary atmospheric phenomena ever observed on an exoplanet. Using the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in Chile, researchers have measured supersonic winds racing around the equator of the distant gas giant WASP-127b. These winds reach speeds of 33,000 kilometers per hour—nearly 18 times faster than the strongest winds found in our Solar System.
“This is something we haven’t seen before,” said Lisa Nortmann, a scientist at the University of Göttingen in Germany and the lead author of the study. “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. This signal shows us that there is a very fast, supersonic, jet wind around the planet’s equator.”
WASP-127b: A Giant with Unusual Features
WASP-127b is located about 520 light-years from Earth and is classified as a “puffy” gas giant, slightly larger than Jupiter but significantly less massive. Since its discovery in 2016, the planet has captured astronomers’ attention for its strange physical properties and dynamic atmosphere. The exoplanet orbits its host star extremely closely, completing one revolution in just 4.2 Earth days, which exposes it to intense heat and likely contributes to its atmospheric complexity.
The newly discovered jet stream is the fastest wind ever recorded on a planet. By comparison, the strongest winds in our Solar System are found on Neptune, where speeds top out at “only” 1,800 kilometers per hour. This unprecedented finding highlights the extreme nature of WASP-127b’s environment. Nortmann emphasized, “It is the fastest wind ever measured in a jet stream that goes around a planet.”
A High-Tech Window into Alien Weather
The discovery was made possible by the CRIRES+ instrument on the ESO’s VLT, a state-of-the-art tool designed to measure the chemical composition and motion of exoplanet atmospheres. By analyzing how starlight passes through WASP-127b’s upper atmosphere, the researchers were able to detect a distinct double-peak signal. This signal revealed that one side of the atmosphere is moving towards Earth while the other is receding—evidence of a high-speed equatorial jet stream.
“This shows that the planet has complex weather patterns just like Earth and other planets of our own system,” noted Fei Yan, a co-author of the study and a professor at the University of Science and Technology of China. The team also found that the planet’s poles are cooler than its equatorial region, and its atmosphere contains both water vapor and carbon monoxide molecules, adding to the picture of a dynamic and layered weather system.
Unraveling the Mysteries of Exoplanet Weather
The findings on WASP-127b shed light on how heat and chemicals are distributed across an exoplanet’s atmosphere. Understanding these dynamics is crucial for building accurate models of exoplanetary climates and unlocking broader insights into planetary formation.
“Understanding the dynamics of these exoplanets helps us explore mechanisms such as heat redistribution and chemical processes, improving our understanding of planet formation and potentially shedding light on the origins of our own Solar System,” said David Cont, a co-author from the Ludwig Maximilian University of Munich. The study also provides a critical step toward decoding how atmospheres on other planets behave, especially those exposed to extreme stellar radiation.
The Future of Exoplanet Research
The discovery of supersonic winds on WASP-127b demonstrates the potential of ground-based telescopes to study alien worlds. While space telescopes like the James Webb Space Telescope (JWST) focus on detecting atmospheric composition, instruments like CRIRES+ excel in measuring the motion and speed of atmospheric gases with high precision.
“This means that we can likely resolve even finer details of the wind patterns and expand this research to smaller, rocky planets,” Nortmann concluded. Such advancements will become even more powerful with the completion of the Extremely Large Telescope (ELT) in Chile. Equipped with the ANDES instrument, the ELT will allow astronomers to study smaller exoplanets and their atmospheres, pushing the boundaries of exoplanetary science.
