At the 2025 annual meeting of the American Astronomical Society, researchers from Pennsylvania State University and the Massachusetts Institute of Technology reported significant findings related to extreme planetary destruction. They studied rocky planets that are literally evaporating due to the intense heat from their stars.
The Pennsylvania team utilized the James Webb Space Telescope (JWST) to measure the internal composition of the disintegrating rocky planet K2-22b for the first time. Located hundreds of light-years from Earth, K2-22b completes an orbit around its star every 9.1 hours at a surface temperature of 2100 K, sufficient to vaporize iron and rock into space.
Nik Tousey, a graduate student at Pennsylvania State University and lead author of one of the studies, stated, "These planets are literally turning their insides out into space, and thanks to JWST, we finally have the opportunity to study their composition and learn what these planets orbiting other stars are really made of."
Meanwhile, the MIT team announced the discovery of the closest and fastest-disintegrating planet, BD+05 4868 Ab, identified using the TESS telescope. This planet exhibits the most impressive dust tails among known disintegrating planets, extending 9 million kilometers and covering more than half of its orbit. BD+05 4868 Ab orbits its star every 30.5 hours.
Notably, BD+05 4868 Ab features two distinct tails—a leading tail composed of larger dust particles akin to sand grains, and a trailing tail made up of smaller particles comparable to soot. The planet's destruction rate is so high that it loses mass equivalent to that of the Moon over a million years and is expected to completely evaporate in one to two million years.
The Pennsylvania researchers also detected unexpected signs of carbon dioxide and nitric oxide in the spectrum of K2-22b—compounds typically associated with icy bodies like comets rather than the mantle of Earth-like planets. This discovery raises new questions about the composition and evolution of such celestial bodies.
Both teams have jointly applied for observations of BD+05 4868 A using the JWST, which may unveil new insights into the internal structures of exoplanets.