Supersonic winds on a nearby exoplanet break all speed records

Astronomers have uncovered a remarkable wind phenomenon on WASP-127b, a gas giant planet that is more than 500 light-years from Earth.

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in Chile, scientists have detected supersonic jetstream winds hurtling around the planet’s equator at astonishing speeds of 33,000 km/h (20,500 mph).

This discovery marks the fastest jetstream ever measured on any known planet and sheds new light on the complex and extreme weather patterns of exoplanets beyond our Solar System.

Giant “puffy” planet with extreme weather

WASP-127b has fascinated scientists since its discovery in 2016. The planet is slightly larger than Jupiter but has a much lower mass, making it a “puffy” gas giant. Its low density suggests that its atmosphere is vastly extended, allowing astronomers to study its composition and climate with relative ease.

Unlike Earth, where storms and winds are driven by temperature differences and planetary rotation, the weather on WASP-127b is governed by far more extreme forces.

The planet is expected to be tidally locked to its host star, meaning one side permanently faces the star while the other remains in perpetual darkness.

This setup leads to dramatic atmospheric conditions, including intense winds that redistribute heat around the planet. However, the sheer velocity of these winds came as a complete surprise to researchers.

Fastest winds on a distant planet

“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,” noted Lisa Nortmann, a scientist at the University of Göttingen in Germany and lead author of the study.

The winds reach a staggering speed of 9 kilometers per second, which is nearly six times faster than the expected rotation speed of the planet.

In comparison, the fastest wind speed recorded in the Solar System was observed on Neptune, where atmospheric winds reach “only” 1,800 km/h (1,118 mph).

WASP-127b’s winds far surpass this, moving at speeds so extreme that they rival the velocity of some of the fastest meteoroids in our Solar System.

Mapping an alien atmosphere

To measure these winds, the research team used the CRIRES+ instrument on ESO’s VLT. This advanced tool allows scientists to analyze the atmosphere of distant planets by studying how starlight filters through the gases surrounding them.

By measuring the specific wavelengths of light absorbed and emitted by molecules in the planet’s upper atmosphere, the team was able to identify water vapor and carbon monoxide molecules in WASP-127b’s air.

But it was the motion of these molecules that provided the most shocking revelation. When the researchers analyzed their speed, they noticed something unexpected – a double peak in the data, showing that one side of the planet’s atmosphere was moving toward Earth while the other was moving away.

This indicated that high-speed jet-stream winds were racing around the equator, rather than simply moving from the day side to the night side as previously expected.

Complex weather system

Beyond detecting the equatorial jetstream, the research team also found intriguing variations in the planet’s temperature. The poles appear cooler than the rest of the planet, suggesting that heat distribution is not uniform.

There is also a noticeable temperature difference between the planet’s morning and evening sides, which hints at complex atmospheric dynamics similar to those found on Earth and other planets in our Solar System.

“This shows that the planet has complex weather patterns just like Earth and other planets of our own system,” noted Fei Yan, a professor at the University of Science and Technology of China and co-author of the study.

Advancing the exoplanet weather research

Until recently, studying the atmospheres of exoplanets was an impossible challenge. For years, astronomers could only determine a planet’s mass and radius, which gave them little information about its climate or atmospheric composition.

However, thanks to powerful ground-based telescopes like ESO’s VLT, researchers can now map weather systems on distant planets and study their wind patterns, temperature gradients, and even cloud formations.

“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,” noted David Cont, a co-author of the paper from the Ludwig Maximilian University of Munich.

Surprisingly, this level of precision is only possible with ground-based telescopes. Current space telescopes, including the James Webb Space Telescope (JWST), do not yet have the required velocity precision to detect wind speeds like those observed on WASP-127b.

This means that facilities on Earth remain essential for pushing the boundaries of exoplanet research.

Wind patterns on planets

With the discovery of supersonic winds on WASP-127b, astronomers are now looking forward to even more detailed investigations into the atmospheres of distant worlds. The upcoming ESO Extremely Large Telescope (ELT), currently under construction in Chile, will play a crucial role in these studies.

Equipped with the ANDES instrument, the ELT will allow scientists to detect even finer details in the wind patterns of exoplanets and expand this research to smaller, rocky planets.

“This means that we can likely resolve even finer details of the wind patterns and expand this research to smaller, rocky planets,” Nortmann concluded.

The discovery of supersonic jetstream winds on WASP-127b is a milestone in exoplanetary science. As telescopes become more advanced, scientists may soon be able to track storm systems, measure rainfall, and even identify weather cycles on distant worlds.

Each new finding brings us one step closer to understanding the diverse and dynamic nature of planets beyond our own Solar System.

The study was published in Astronomy & Astrophysics.

Image Credit: ESO/L. Calçada

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–