Unidentified Substance Absorbs Light on Pluto and Titan

Astronomers detected an unidentified compound absorbing light on the surfaces of Pluto and Saturn’s moon Titan. Data from the James Webb Space Telescope showed a narrow absorption band on Titan and a broader version of the same wavelengths on Pluto.

The two bodies differ sharply in temperature, atmospheric density, and surface conditions. Titan maintains a thick nitrogen-methane atmosphere and liquid hydrocarbon seas, while Pluto is far colder with a thin atmosphere. Despite these differences, both atmospheres contain nitrogen and methane that produce haze particles that settle on the surface.

Researchers compared the observed absorption feature against laboratory spectra and known atmospheric compounds. None matched exactly. A few candidates came close, suggesting the mystery substance may be a modified or mixed form of those compounds, possibly with different grain sizes on each body.

JWST observations are already collected and may help locate the substance on Titan’s surface. Laboratory experiments are testing whether slight modifications to near-matching compounds can reproduce the observed spectrum. NASA’s Dragonfly spacecraft, scheduled to launch in 2028 and land on Titan in 2034, is expected to provide direct surface measurements.