Prepare to be blown away: Astronomers have recorded the most powerful planetary wind thus far — a force that pummels a giant exoplanet with gales faster than the speed of sound.
The jet stream sweeps WASP-127b’s equator at over 20,000 miles per hour. That’s about 1,000 times more powerful than the gales that buffet Mt. Washington in New Hampshire — one of the windiest places on Earth. The exoplanet’s winds blow 18 times faster than those on Neptune, which has the strongest winds ever measured in the Solar System.
The discovery, made by using the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in Chile, was published in Astronomy & Astrophysics.
Surpassing Wind Records
The massive gas planet is a tad larger than Jupiter — but has a fraction of its mass. Ever since WASP-127b’s discovery in 2016 (over 500 light years from Earth) astronomers have been fascinated by how its atmosphere behaves — and the extreme weather it produces.
“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,” Lisa Nortmann, a scientist at the University of Göttingen, Germany, and lead author of the study said in a press release. “This signal shows us that there is a very fast, supersonic, jet wind around the planet’s equator.”
The jet winds move almost six times faster than the speed of the planet’s rotation. “This is something we haven’t seen before,” Nortmann said.
Read More: 5 Planets with Extreme (and Weird) Weather Patterns in Our Solar System
Measuring Particle Movement
The astronomers first measured how the light of WASP-127b’s host star travels through the planet's upper atmosphere. Then they probed its composition, finding both water vapor and carbon monoxide molecules there. Finally, they clocked the speed at which these molecules moved.
They were astounded by its speed. But they were also surprised to see that one side of the atmosphere moved toward the telescope and the other side blew away. The researchers concluded that powerful jet stream winds around the equator explained that phenomenon.
As on Earth, the WASP-127b’s poles are cooler than the rest of the planet. Temperatures shift slightly between it’s morning and evening sides.
New Frontiers in Space Weather
The field of exoplanet research is rapidly advancing. But it faces some limitations. For example, weather studies like this one can only be conducted with ground-based telescopes. The instruments mounted on existing space telescopes lack the ability to measure wind velocity with the necessary precision.
Bigger, stronger instruments, like ESO’s Extremely Large Telescope (under construction close to the VLT in Chile) may allow researchers to look for extreme planetary weather even farther away. That leaves us with the question of how long will this wind record last?
Article Sources
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Astronomy & Astrophysics. CRIRES+ transmission spectroscopy of WASP-127 b
Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.
