For the first time, scientists have mapped the true shape of a distant exoplanet orbiting a star 1,000 light-years away, offering the best glimpse yet into a world far beyond our solar system.
In a recent paper in Nature Astronomy, an international team of scientists presented a mathematical model that moves beyond the idealized, perfectly spherical shapes astronomers typically use to capture an exoplanet‘s imperfect reality.
Data for the exoplanet project come from the James Webb Space Telescope (JWST), which has allowed astronomers to peer much deeper into the distant universe than ever before. The achievement marks a major step toward characterizing the physical features of our universe.
The True Shape of an Exoplanet
The planet in question is WASP-17b, a hot Jupiter—a gas giant orbiting so close to its parent star that its atmosphere reaches extreme temperatures.
Based on the team’s findings, the circular shape traditionally used in mathematical models wasn’t entirely off the mark, but the exoplanet’s actual form is slightly more egg-shaped, consistent with theoretical expectations. Although this deformation may seem relatively minor, particularly since Earth itself is an oblate spheroid, it reveals important details about the extreme conditions on this distant world.
“This is proof of concept that planets are in fact 3D objects, and that consistently, as they go around their star, what we predict should be happening is happening,” said first author Lili Alderson, a Klarman Postdoctoral Fellow in the College of Arts and Sciences. “To move beyond computational exercises and see it for real is a different matter.”
Modeling in Three Dimensions
“Planets are temperamental, their atmospheres complex and chaotic,” explained second author Hannah Wakeford. “The fact that all of these numbers came together and showed us this very structured, dynamical picture of this giant world over 1,000 light-years away was just really exciting.”
The work builds on earlier techniques such as eclipse mapping, which uses changes in light as an exoplanet passes behind its host star to investigate its properties.
For the new research, the team developed a technique called transit mapping, or the transmission strings method, which examines changes in starlight as a planet passes in front of its host star. By measuring light passing through different regions along the edge of the planet’s atmosphere, researchers can obtain a more detailed picture of its shape than traditional methods, which generally average these measurements.
“Rather than assuming your planet is a circle with the same radius all the way around, our technique allows you to pull out different distances from the center to the edge of the planet,” Alderson said. “We’re able to go around the edge. So, we’ve gone from a ring to understanding where on the ring the gemstones are, so to speak.”
A Scorching Exoplanet
The newly mapped deformation of WASP-17b’s atmosphere is associated with the extreme conditions on the planet, including intense heating and atmospheric winds. The findings provide an important demonstration of how astronomers can investigate the shapes and atmospheric dynamics of distant exoplanets.
The deformation also closely matches theoretical predictions. WASP-17b is believed to be tidally locked, meaning one side permanently faces its host star while the other remains in darkness.
Researchers had predicted that hot atmospheric gases circulating from the planet’s dayside toward its cooler nightside could produce an equatorial bulge, creating an asymmetry that is consistent with the new observations.
Beyond revealing the shapes of distant planets, the technique could also help astronomers investigate atmospheric circulation and weather patterns on other worlds.
“Having this very robust mathematical model that we can apply to this state-of-the-art data is incredibly exciting,” Wakeford said. “The results are a really beautiful demonstration of the dynamics that are going on in these multidimensional and multifaceted worlds.”
“The first-ever use of this new technique shows us that our understanding of these planets is correct, that our different methods all agree with each other,” Alderson concluded. “And that the future is very bright for being able to use these techniques to get deep dives on many different planets in the coming years.”
The paper, “Nonlocal Evolution of Magnetic Helicity across the Magnetohydrodynamic–Kinetic Interface,” appeared in The Astrophysical Journal Letters on October 9, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.