Astronomers have made a remarkable discovery of exceptionally strong winds whipping around the equator of WASP-127b, a massive exoplanet. These winds can reach extraordinary speeds of up to 33,000 km/h, marking the fastest jet-stream of this type ever recorded on any planet. This finding was revealed through observations made using the Very Large Telescope (VLT) of the European Southern Observatory in Chile, offering valuable insights into the atmospheric conditions of this distant exoplanet.
While tornadoes, cyclones, and hurricanes create chaos on Earth, researchers have now identified planetary winds on a vastly different scale, located far beyond our Solar System. Since its detection in 2016, scientists have been exploring the atmospheric conditions of WASP-127b, a colossal gas giant situated over 500 light-years away. Although slightly larger than Jupiter, it has much less mass, leading to its ‘puffy’ appearance. Recently, an international team has made an astonishing breakthrough: they have found supersonic winds swirling across the planet.
“We observed that part of the atmosphere is rushing towards us at a high rate, while another section is moving away from us at the same speed,” explains Lisa Nortmann, a researcher from the University of Göttingen, Germany, and the lead author of the study. “This observation suggests a rapid, supersonic jet wind encircling the planet’s equator.”
With speeds reaching approximately 9 km per second (nearly 33,000 km/h), these jet winds are nearly six times faster than the planet’s rotational speed.* “This is unprecedented,” Nortmann remarks. It stands as the swiftest wind recorded in a jetstream around any planet, surpassing the fastest wind noted in our Solar System on Neptune, which travels at ‘only’ 0.5 km per second (or 1800 km/h).
The researchers, whose work is published in Astronomy & Astrophysics, utilized the CRIRES+ instrument on the VLT to map the weather and analyze the composition of WASP-127b. By examining how the light from the host star passes through the planet’s upper atmosphere, they were able to identify its chemical makeup. Their findings confirmed the presence of water vapor and carbon monoxide in the atmosphere. However, during their investigation into the material’s speed within the atmosphere, they were surprised to discover a dual peak, suggesting that one hemisphere of the atmosphere is advancing towards us, while the other is retreating at a swift pace. Their analysis led to the conclusion that powerful jetstream winds encircle the planet’s equator, clarifying this unexpected observation.
As they continued to chart their weather analysis, the team also noted that the poles of WASP-127b are cooler compared to the rest of the planet. They detected a slight temperature variation between the planet’s morning and evening sides. “This indicates that WASP-127b has intricate weather patterns much like those found on Earth and other planets in our own Solar System,” states Fei Yan, a co-author and professor at the University of Science and Technology of China.
The study of exoplanets is experiencing rapid advancements. Just a few years ago, astronomers could only measure characteristics like mass and diameter of planets beyond the Solar System. However, modern telescopes like the VLT enable scientists to track weather conditions on these far-off worlds and examine their atmospheres. “Grasping the dynamics of these exoplanets enhances our understanding of phenomena such as heat distribution and chemical processes, which aids in comprehending planet formation and may even illuminate the origins of our own Solar System,” notes David Cont from Ludwig Maximilian University of Munich, Germany, who also contributed to the research.
Interestingly, current studies of this nature can only be conducted using ground-based observatories because existing instruments on space telescopes lack the required precision to measure velocity accurately. The ESO’s Extremely Large Telescope, which is currently being built near the VLT in Chile, along with its ANDES instrument, is expected to provide even deeper insights into the weather patterns of remote planets. “This will likely allow us to discern even finer details of wind patterns and broaden our research to include smaller, rocky planets,” Nortmann concludes.
Note
* Although the team has not directly measured the planet’s rotation speed, they suspect that WASP-127b is tidally locked. This means that the period it takes to rotate on its own axis is equal to the time it takes to orbit its star. By understanding the size of the planet and its orbital duration, they can estimate its rotation speed.
