Webb telescope reveals ancient chemical composition of interstellar comet 3I/ATLAS (esa.int)

• JWST NIRSpec measurements show extremely high deuterium and low carbon-13 in comet 3I/ATLAS.
• The isotopic ratios suggest formation 10–12 billion years ago.
• The comet is chemically distinct from Solar System comets.

"The James Webb Space Telescope measured high deuterium and low carbon-13 in interstellar comet 3I/ATLAS, indicating it formed 10–12 billion years ago during cosmic noon. The ratios differ from Solar System comets, suggesting a very cold origin."