NASA's Webb discovers water and a new enigma in a rare main-belt comet.

The James Webb Space Telescope has detected water vapour around a comet in the main asteroid belt for the first time, proving that water from the primordial Solar System can be preserved as ice in that region. However, the successful detection of water comes with a new puzzle: unlike other comets, Comet 238P/Read had no detectable carbon dioxide. The missing carbon dioxide was a bigger surprise. The next step is taking the research beyond Comet Read to see how other main-belt comets compare.