Astronomers detect ferocious jet-stream winds on alien planet

Discover the fastest jet-stream winds on exoplanet WASP-127b, reaching 33,000 km per hour, driven by intense stellar radiation.

In the earth’s upper atmosphere, a fast-moving band of air called the jet stream blows with winds of more than 442 km per hour, but they are not the strongest in our solar system. The comparable high-altitude winds on Neptune reach about 2,000 km per hour. Those, however, are a mere breeze compared to the jet-stream winds on a planet called WASP-127b.

Astronomers have detected winds howling at about 33,000 km per hour on this large gaseous planet, located in our Milky Way galaxy approximately 520 lightyears from the earth in a tight orbit around a star similar to our sun.

The supersonic jet-stream winds circling WASP-127b at its equator are the fastest of their kind on any known planet.

“There is an extremely fast circumplanetary jet wind found on the planet. The velocity of the winds is surprisingly high,” said astrophysicist Lisa Nortmann of the University of Göttingen in Germany, lead author of the study published on Tuesday in the journal Astronomy & Astrophysics.

More than 5,800 planets beyond our solar system, called exoplanets, have been discovered. WASP-127b is a type called a hot Jupiter, a gas giant that orbits very close to its host star. WASP-127b’s diameter is about 30% larger than Jupiter, our solar system’s largest planet. But its mass is only about 16% that of Jupiter, making it one of the puffiest planets ever observed.

“WASP-127b is a gas giant planet, which means that it has no rocky or solid surface beneath its atmospheric layers. Instead, below the observed atmosphere lies gas that becomes denser and more pressurized the deeper one goes into the planet,” said astrophysicist and study co-author David Cont of Ludwig Maximilian University of Munich in Germany.

It orbits its star every roughly four days at just about 5% of the distance between the earth and the sun, leaving it scorched by stellar radiation. Like our moon is to the earth, one side of WASP-127b perpetually faces its star - the day side. The other side always faces away - the night side. Its atmosphere is about 2,060 degrees Fahrenheit (1,400 degrees Kelvin/1,127 degrees Celsius), with its polar regions less hot than the rest.