Astronomers have made an extraordinary discovery—for the first time, scientists have directly observed two alien planets disintegrating before our eyes. These exoplanets, orbiting different stars, are shedding their outer layers into space, revealing their interiors in an unprecedented way. The James Webb Space Telescope (JWST) and NASA’s Transiting Exoplanet Survey Satellite (TESS) detected these dying worlds, providing a rare glimpse into the extreme conditions that cause planets to break apart. This discovery not only changes our understanding of planetary evolution but also opens new doors for studying the deep composition of exoplanets.
A Groundbreaking Study on Planetary Destruction
The findings on these disintegrating exoplanets were detailed in two papers currently under peer review, published as preprints on arXiv. The studies, led by researchers from Penn State University and MIT, provide spectral fingerprints of the planets’ atmospheric compositions, offering rare insights into planetary interiors. The research suggests that these planets are being slowly stripped apart by their extreme environments, a process that has never been observed in such detail before.
“It’s a remarkable and fortuitous opportunity to understand terrestrial planet interiors,” said Jason Wright, a professor of astronomy and astrophysics at Penn State University and a co-author of the study. With these findings, scientists now have a rare chance to analyze what lies beneath a planet’s surface, something that remains impossible even for planets in our own solar system.
The First Planet: K2-22b—A World Boiling Into Space
The first planet, K2-22b, is a Neptune-sized rocky world located hundreds of light-years away. It orbits its host star in just nine hours, meaning it is locked in an extreme cosmic inferno. The planet’s surface temperatures soar beyond 3,320 degrees Fahrenheit (1,826 degrees Celsius)—hot enough to vaporize rock and metal. As a result, K2-22b is literally boiling away, shedding its outer layers into space.
Observations from JWST confirmed that the evaporated material forms an elongated, comet-like tail, stretching behind the planet as it races around its star. This effect is caused by intense radiation pressure, which blows away vaporized rock and dust, sculpting it into a dramatic cosmic plume. The planet is expected to lose most of its mass over time, shrinking into a tiny, lifeless core before eventually vanishing entirely.
The Second Planet: BD+054868Ab—A Planet with Two Massive Tails
The second disintegrating planet, BD+054868Ab, is even more striking. It is the closest evaporating exoplanet to Earth ever discovered, making it a perfect laboratory for studying extreme planetary conditions. Unlike K2-22b, BD+054868Ab is losing material at an astonishing rate, forming not one, but two massive tails. These tails are composed of larger, sand-sized particles in the leading plume and smaller, soot-sized grains in the trailing one.
Together, the planet’s tails extend over 5.6 million miles (9 million kilometers), covering nearly half of its orbit around its star. Scientists estimate that BD+054868Ab is shedding a moon’s worth of material every million years. Based on its current rate of destruction, astronomers predict that it will completely disappear in 1 to 2 million years—a mere blink of an eye in cosmic terms.
“These planets are literally spilling their guts into space for us,” said Nick Tusay, a graduate student at Penn State University and the lead author of the JWST study. “With JWST, we finally have the means to study their composition and see what planets orbiting other stars are really made of.”
What These Planets Reveal about Exoplanetary Science
These disintegrating exoplanets are more than just cosmic oddities—they provide a crucial window into planetary formation and evolution. Most exoplanets discovered so far are fully intact, meaning scientists can only study their outer atmospheres. However, these dying worlds expose their interior compositions, offering direct insights into what planets are made of beneath their surfaces.
While studying K2-22b, JWST detected gases like carbon dioxide and nitric oxide, which are usually associated with icy bodies rather than terrestrial planets. This suggests that K2-22b may have formed much farther from its star before migrating inward due to gravitational disturbances. Meanwhile, BD+054868Ab’s dust tails provide crucial data on how planetary materials interact with stellar radiation, influencing everything from planetary climate to potential habitability.
