Michael S. P. Kelley

Comet 3I/ATLAS was spotted when it entered the Solar System from interstellar space. The James Webb Telescope split the light from its gas cloud into a rainbow, a spectrum, and in this pattern, the lines of rare molecules with deuterium (heavy hydrogen) appeared.

In the summer of 2021, comet 7P/Pons-Winnecke put on quite a show. A network of telescopes, the Las Cumbres Observatory, tracked it for nearly three months and counted eight sudden outbursts.

In March 2023, the James Webb Space Telescope pointed its instruments at the short-period comet 81P/Wild 2. This celestial body, about the size of a small town (nucleus radius around 1.77 km), is already familiar to scientists: in 2006, the Stardust probe flew through its tail and collected dust samples that were later studied in Earth laboratories.