The weather inside our Solar System is tough to track. But even tougher to track is the weather outside our Solar System. Implementing all four of the telescope units of the European Southern Observatory’s Very Large Telescope (VLT), a team of researchers has observed the weather on WASP-121b, or Tylos, an exoplanet around 900 light-years away, identifying the layers of its atmosphere for the first time.
Reporting their results in a study in Nature, the team identified three layers of churning, chemical-carrying winds — loaded with elements like iron, sodium, hydrogen, and titanium — laying the foundations for future studies of faraway worlds.
“This planet’s atmosphere behaves in ways that challenge our understanding of how weather works — not just on Earth, but on all planets,” said Julia Victoria Seidel, a study author and researcher at the European Southern Observatory, according to a press release. “It feels like something out of science fiction.”
A Sci-Fi Find
WASP-121b isn’t at all like Earth. For one thing, the exoplanet is a gas giant without a solid surface, composed of churning clouds. For another, it orbits the star WASP-121 at such close proximity that the side of the exoplanet that always faces the star is scalding, soaring to temperatures of around 3,320 degrees Fahrenheit and above.
Observing the exoplanet with all of the VLT’s four telescope units at once, the team of researchers was able to observe the structure of WASP-121b’s atmosphere. Specifically, they found a bottom layer of iron-laden winds, a middle layer of sodium-laden winds, and an upper layer of hydrogen-laden winds.
The middle layer, a jet stream that spans the scorching side of WASP-121b, “rotates material around the planet’s equator, while a separate flow at lower levels of the atmosphere moves gas from the hot side to the cooler side,” Seidel said in the release. “Even the strongest hurricanes in the Solar System seem calm in comparison.”
According to the press release, the study represents the first time that researchers have seen and separated out the specific layers of an exoplanet’s atmosphere and the first time that they’ve studied this specific structure in any atmosphere, whether inside our Solar System or outside.
“What we found was surprising,” Seidel said in the release. “This kind of climate has never been seen before on any planet.”
Read More: From Billions to Trillions Light Years Away, These are the Furthest Stars and Exoplanets From Earth
Exposing Alien Atmospheres
A single one of the VLT’s telescope units can observe objects that are four billion times fainter than those that we can observe ourselves without a telescope, and all four of the VLT’s telescope units can capture objects that are much fainter than that when they’re combined.
As such, the team turned to ESPRESSO, an instrument that’s attached to the VLT that consolidates the abilities of all four telescope units. Capturing four times the light of any one of the telescope units, ESPRESSO allows the VLT to find far fainter objects, like WASP-121b, and the chemical winds whipping within its atmosphere.
“The VLT enabled us to probe three different layers of the exoplanet’s atmosphere in one fell swoop,” said Leonardo A. dos Santos, another study author and a researcher at the Space Telescope Science Institute in Baltimore, according to the release. “It’s the kind of observation that is very challenging to do with space telescopes, highlighting the importance of ground-based observations of exoplanets.”
Read More: How the James Webb Space Telescope Will Search for Extraterrestrial Life
Expanding the Search
Also identified in the lowest layer of WASP-121b’s atmosphere were the traces of titanium, reported in a related study in Astronomy & Astrophysics.
“It’s truly mind-blowing that we’re able to study details like the chemical makeup and weather patterns of a planet at such a vast distance,” said Bibiana Prinoth, another study author and a student at Lund University in Sweden and at the European Southern Observatory, in the release.
To find other exoplanets, the team is already looking to larger telescopes, like the ESO’s Extremely Large Telescope (ELT), which is scheduled to start scientific observations in 2028.
“The ELT will be a game-changer for studying exoplanet atmospheres,” Prinoth said in the release. “This experience makes me feel like we’re on the verge of uncovering incredible things we can only dream about now.”
Read More: How the James Webb Space Telescope Takes Such Stunning Pictures
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Nature. Vertical Structure of an Exoplanet’s Atmospheric Jet Stream
ESO. Very Large Telescope
ESO. ESPRESSO
Astronomy & Astrophysics. Titanium Chemistry of WASP-121 b With ESPRESSO in 4-UT Mode
Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.
