This artist’s visualisation of WASP-127b, a giant gas planet located about 520 light-years from Earth, shows its newly discovered supersonic jet winds that move around the planet’s equator. With a speed of 9km per second (33,000km/h), this is the fastest jetstream of its kind ever measured in the Universe.

By tracking the speed of molecules in the atmosphere with the CRIRES+ instrument on ESO’s Very Large Telescope, researchers found that one side of the planet’s atmosphere is moving towards us and the other away from us. This indicates that there is a powerful wind current going around the planet. Credit: ESO/ L Calçada. CC BY.

Astronomers have discovered extremely powerful winds pummelling the equator of WASP-127b, a giant exoplanet far outside our Solar System.

Reaching speeds up to 33 000 km/h, the winds make up the fastest jetstream of its kind ever measured on a planet.

The discovery was made using the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in Chile and provides unique insights into the weather patterns of a distant world.

Different scale

Tornados, cyclones and hurricanes wreak havoc on Earth, but scientists have now detected planetary winds on an entirely different scale, far outside the Solar System.

Ever since its discovery in 2016, astronomers have been investigating the weather on WASP-127b, a giant gas planet located over 500 light-years from Earth.

The planet is slightly larger than Jupiter, but has only a fraction of its mass, making it ‘puffy’.

An international team of astronomers have now made an unexpected discovery: supersonic winds are raging on the planet.

Lead author says Lisa Nortmann, a scientist at the University of Göttingen, Germany, said: “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.”

At 9 km per second (which is close to a whopping 33,000 km/h), the jet winds move at nearly six times the speed at which the planet rotates.

Nortmann said: “This is something we haven’t seen before.”

It is the fastest wind ever measured in a jetstream that goes around a planet.

In comparison, the fastest wind ever measured in the Solar System was found on Neptune, moving at ‘only’ 0.5 km per second (1,800 km/h).

Double peak

The team mapped the weather and make-up of WASP-127b using the CRIRES+ instrument on ESO’s VLT.

By measuring how the light of the host star travels through the planet’s upper atmosphere, they managed to trace its composition.

Their results confirm the presence of water vapour and carbon monoxide molecules in the planet’s atmosphere.

But when the team tracked the speed of this material in the atmosphere, they observed — much to their surprise — a double peak, indicating that one side of the atmosphere is moving towards us and the other away from us at high speed.

The researchers conclude that powerful jetstream winds around the equator would explain this unexpected result.

Further building up their weather map, the team also found that the poles are cooler than the rest of the planet.

There is also a slight temperature difference between the morning and evening sides of WASP-127b.

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

The field of exoplanet research is rapidly advancing. Up until a few years ago, astronomers could measure only the mass and the radius of planets outside the Solar System.

Today, telescopes like ESO’s VLT already allow scientists to map the weather on these distant worlds and analyse their atmospheres.

Co-author David Cont, from the Ludwig Maximilian University of Munich, Germany, said: “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.”

Interestingly, at present, studies like this can only be done by ground-based observatories, as the instruments currently on space telescopes do not have the necessary velocity precision.

ESO’s Extremely Large Telescope — which is under construction close to the VLT in Chile — and its ANDES instrument will allow researchers to delve even deeper into the weather patterns on far-away planets.

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

The research is published in Astronomy and Astrophysics.