Astronomers have made an extraordinary discovery that promises to deepen our understanding of the weather systems on distant planets. On WASP-127b, a giant exoplanet located over 500 light-years away from Earth, scientists have found wind speeds of up to 33,000 km/h. These powerful winds make up the fastest jet stream ever measured in a planetary atmosphere. The discovery was made using the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in Chile and offers new, detailed insights into the atmospheric dynamics of a distant world.
A Giant Exoplanet With Unexpected Weather Patterns
WASP-127b, which was discovered in 2016, has captured the attention of astronomers due to its peculiar characteristics. Slightly larger than Jupiter but only a fraction of its mass, the exoplanet is notably “puffy.” This makes it an ideal target for scientists studying gas giants and their atmospheric behavior. Despite being similar to Jupiter in size, the low mass of WASP-127b allows it to have a much lower density, giving it a distinctive profile in the astronomical community.
While much has been learned about its general characteristics, one crucial element remained elusive—what is the weather like on this massive gas planet? Astronomers had suspected that WASP-127b could have stormy conditions given its size and location within the “hot Jupiter” category. These types of exoplanets are known to have extreme weather due to their proximity to their host stars, which exposes them to intense heating and temperature fluctuations. However, what they found was a phenomenon beyond expectations: supersonic winds dominating the equator.
The winds measured on WASP-127b are nothing short of astonishing. At speeds of 9 kilometers per second (roughly 33,000 km/h), these winds move at nearly six times the planet’s rotational speed. In comparison to anything measured within our solar system, the winds on WASP-127b are shockingly fast. The fastest winds on a known planet within our own solar system were observed on Neptune, which has jet streams moving at 0.5 km per second (approximately 1,800 km/h). The winds on WASP-127b dwarf Neptune’s, signifying just how extreme the weather on this far-off world is.
The Science Behind the Discovery
To unravel the details of WASP-127b’s weather, an international team of astronomers conducted cutting-edge research using the CRIRES+ spectrograph on ESO’s VLT. The team combined their observations with intricate modeling to map the atmosphere and analyze the composition of WASP-127b. By studying the light that traveled through the planet’s upper atmosphere, they were able to identify the presence of molecules like water vapor and carbon monoxide. This instrumental analysis was crucial to understanding the planet’s weather systems in greater detail.
Their most unexpected finding came from tracking the movement of these molecular gases through the atmosphere. When they analyzed the speed at which these gases were moving, the data showed a double peak in the measurements—suggesting that one side of the planet’s atmosphere was moving toward Earth while the other side was moving away, both at remarkably high velocities.
The researchers concluded that these unusually fast winds, located in a jet stream along the planet’s equator, are the primary cause of this unexpected double peak signal. The jet stream winds of WASP-127b are so strong that they are distorting the way light interacts with the planet’s atmosphere in a measurable way, a phenomenon previously unobserved in exoplanet research.
Comparing WASP-127b’s Jet Stream With Earth’s Weather Systems
By continuing to map the planet’s weather patterns, the team discovered additional complexities. Similar to Earth, there are temperature differences between different regions of the planet. The poles of WASP-127b are cooler compared to other areas, an effect also seen on our own planet. Moreover, there is a slight temperature contrast between the morning and evening sides of the planet, indicating that heat redistribution across the planet is happening.
This finding gives insight into the planet’s dynamic weather, confirming that WASP-127b’s atmospheric conditions are complex and highly variable, just like Earth’s own weather systems. Although we often think of exoplanets as being static and unchanging, the reality is that many of them experience highly dynamic and dramatic weather patterns similar to those found in our solar system.
The Path to Mapping Exoplanet Weather
The ability to measure and map the weather systems of exoplanets, like those on WASP-127b, marks a significant advancement in the field of exoplanet research. Just a few years ago, astronomers were only able to measure basic parameters like the mass, radius, and orbital characteristics of planets outside our solar system. Now, with advanced instruments like CRIRES+ and the ESO’s VLT, scientists have reached new frontiers in the study of exoplanet atmospheres, uncovering far more intricate details about the physical and chemical processes occurring on these distant worlds.
This kind of research contributes significantly to our broader understanding of exoplanets. According to the research team, analyzing the atmospheric dynamics of these alien worlds allows scientists to explore phenomena like heat redistribution and the chemical processes that shape their climates. As a result, studying exoplanet weather may also give us clues about the processes behind planet formation, potentially providing insight into the origins of our own solar system.
It is worth noting that current research on exoplanet atmospheres, especially detailed mapping of their weather systems, is only possible through ground-based observatories. Although space telescopes have revolutionized our understanding of the cosmos, they still lack the necessary velocity precision to study the atmospheric dynamics of far-off planets like WASP-127b. ESO’s Extremely Large Telescope (ELT), currently under construction in Chile, promises to push the boundaries of exoplanet research even further. Equipped with advanced instruments like ANDES, the ELT will allow researchers to resolve even finer details of weather patterns on exoplanets.
The Implications of this Discovery
The study of extreme winds and weather patterns on exoplanets has broader implications, not just for understanding distant worlds, but also for refining models of planetary systems in general. WASP-127b’s supersonic jet winds, in particular, challenge our perceptions of planetary atmospheres, indicating that these phenomena can occur in surprising and previously unknown ways. Researchers hope that continuing studies of gas giants and rocky exoplanets will eventually allow us to comprehend their habitability and the kinds of environments in which life might exist.
As technology progresses and new instruments are developed, researchers will be able to extend these techniques to smaller, rocky exoplanets—potentially finding weather systems and other features that could inform our search for habitable worlds beyond our solar system.
By exploring the dynamics of planets like WASP-127b, scientists are able to probe the boundaries of current planetary science. More than just pushing the limits of what we know about distant exoplanets, discoveries like these also spark new questions. How do extreme atmospheric winds form on massive planets? What are their long-term effects on the planet’s climate and atmosphere? What can these findings tell us about the potential for life elsewhere in the galaxy? These discoveries have just scratched the surface of a rapidly expanding field that promises more surprising revelations about the universe.
Conclusion
The discovery of supersonic winds on WASP-127b highlights a pivotal moment in the study of exoplanetary weather systems. Astronomers have shown that some far-off worlds can have weather patterns that rival the complexity of Earth’s. WASP-127b’s fast-moving jet streams, along with other atmospheric features like temperature variations and chemical compositions, offer scientists an unprecedented glimpse into the dynamics of a distant planet. With the coming advancements in observational tools, like ESO’s Extremely Large Telescope, researchers are poised to continue making groundbreaking discoveries that expand our understanding of planetary systems—potentially uncovering new details about the formation of our own solar system and the prospects for life on other planets.
Reference: L. Nortmann et al, CRIRES+ transmission spectroscopy of WASP-127 b, Astronomy & Astrophysics (2025). DOI: 10.1051/0004-6361/202450438