Webb telescope finds extreme debris disks fall into two families, pointing to different planet-shattering collisions

1 October 2026

NASA said on 1 October 2026 that astronomers using the James Webb Space Telescope have sorted extreme debris disks into two distinct classes by their mineral composition.
The team studied 21 such systems, 16 observed with Webb and 5 drawn from archival Spitzer Space Telescope data, using mid-infrared spectra.
About one third of the disks are silica-rich, which points to high-energy collisions between Mars-sized bodies with a great deal of vaporisation.
The remaining two thirds are silica-poor, indicating lower-energy impacts between Moon-sized objects.
Silica-rich disks were found only around stars younger than 300 million years.
The work was led by Kate Su of the Space Science Institute in Boulder, Colorado, with Agnes Kospal and Attila Moor of Konkoly Observatory in Budapest, and was published in The Astrophysical Journal.
NASA compared the events to the impact of the Mars-sized body Theia with the early Earth, about 100 million years after the solar system formed, which is thought to have made the Moon.