Supersonic jet streams reach 20,500 MPH on this hot Jupiter exoplanet, surpassing Earth’s and Neptune’s atmospheric winds.
Astronomers have discovered winds howling at nearly 20,500 miles (33,000 kilometers) per hour on the massive gas planet WASP-127b, located about 520 light-years away from Earth in the Milky Way galaxy. This planet orbits its star at a distance much closer than Earth to the sun.
These supersonic jet-stream winds circling WASP-127b’s equator are the fastest known winds on any planet.
“The planet contains an extraordinarily rapid circumplanetary jet wind. The wind velocity is surprisingly high,” said Lisa Nortmann, the lead author of the study, from the University of Göttingen, Germany, who published the findings in Astronomy & Astrophysics on Tuesday.
With more than 5,800 exoplanets identified beyond our solar system, WASP-127b is classified as a “hot Jupiter,” a gas giant orbiting exceptionally close to its host star. It has a diameter roughly 30% larger than Jupiter, yet its mass is only about 16% of Jupiter’s, making it one of the least dense planets ever observed.
WASP-127b is a gas giant, meaning it has no solid surface but consists of a dense, pressurized atmosphere that becomes thicker the deeper you go.
It orbits its star every four days at only 5% of the Earth-sun distance, resulting in extreme stellar radiation. One side of the planet always faces its star, similar to the Moon’s relationship with Earth, creating a day side and a night side. Its temperature reaches 2,060°F (1,127°C), with the poles cooler than the rest.
WASP-127b’s atmosphere, like Jupiter’s, is primarily hydrogen and helium, but it also contains more complex compounds like carbon monoxide and water, as revealed in this study.
“The main source of energy for these winds is the intense irradiation from the host star,” said co-author David Cont, adding that multiple factors contribute to the planet’s wind patterns.
The study used the CRIRES+ instrument at the European Southern Observatory’s Very Large Telescope to track molecular speeds in the planet’s atmosphere. This work opens new avenues in understanding exoplanet atmospheres by moving beyond basic temperature and chemical analysis to explore three-dimensional wind patterns and atmospheric dynamics.
