NASA's James Webb Space Telescope Watched a Planet Get Absolutely Scorched

A distant exoplanet named HD 80606 b is experiencing some of the most extreme temperature swings ever recorded, and NASA’s James Webb Space Telescope caught the action. The planet’s highly elliptical orbit brings it blisteringly close to its home star, then flings it far out again, causing its atmosphere to heat up by over a thousand degrees in just hours. This violent planetary weather offers a unique laboratory for studying atmospheric dynamics under extreme conditions—insights that could reshape our understanding of exoplanet climates.

NASA’s James Webb Space Telescope (JWST) observed HD 80606 b, a gas giant located about 190 light-years away in the constellation Ursa Major. The observation campaign, led by a team of astronomers, tracked the planet as it made its closest approach to its star—a point called periastron—where stellar radiation is intense enough to raise surface temperatures from roughly 500°C to over 1,200°C in a matter of hours. The brief but dramatic heating event was captured in infrared, revealing how the planet’s atmosphere responds to sudden energy input.

HD 80606 b is no ordinary exoplanet. Its orbit is one of the most eccentric known, with an eccentricity of 0.93—comparable to a comet’s path. A full year on this world lasts 111 Earth days, but the vast majority of that orbital energy is released during a short 18-hour window near its star. This extreme orbital configuration makes HD 80606 b an ideal target for studying how planetary atmospheres absorb and dissipate heat in real time. The JWST observations mark the first time such a temperature spike has been measured with such precision.

During the observation, the JWST’s Mid-Infrared Instrument (MIRI) recorded the planet’s brightness before, during, and after periastron. The data showed that the planet’s dayside temperature surged by more than 700 Kelvin in less than a day—a rate far faster than any known weather event in our solar system. After the heat pulse, the scorched HD 80606 b began to cool, but at a slower pace, suggesting that some of the energy is trapped in deeper atmospheric layers or redistributed by powerful winds. The researchers, led by astronomer Tiffany Kataria at NASA’s Jet Propulsion Laboratory, published their findings in a recent study.

The findings have broader implications for exoplanet science. Most exoplanets discovered to date orbit relatively close to their stars, but their eccentricities vary widely. By understanding how energy is transported on HD 80606 b, scientists can refine models that predict temperature patterns and cloud formation on other worlds—including potentially habitable ones. This case also demonstrates how JWST’s sensitivity can capture transient events, unlocking new avenues for studying planetary dynamics beyond static snapshots.

Moving forward, astronomers plan to conduct follow-up observations of HD 80606 b during multiple orbits to see if the temperature patterns repeat reliably. They also hope to use JWST’s spectroscopy capabilities to probe the chemical composition of the planet’s atmosphere during the heat spike, specifically looking for molecules like carbon dioxide and water vapor that might trace circulation. As JWST continues to monitor this scorched planet, it may offer a blueprint for understanding extreme climates across the galaxy—and a cautionary tale about worlds just a little too close to their sun.