Ice in interstellar comet 3I/ATLAS has 10 times more deuterium than solar system comets

Analysis of interstellar comet 3I/ATLAS shows its ices contain deuterium at concentrations more than ten times higher than any known solar system comet, with carbon isotopic ratios outside the range of any measured body. The ices formed 10–12 billion years ago, before the Sun existed. Dominique Bockelée-Morvan of the Paris Observatory presented the findings at the PIAZZI 200 conference in Palermo.

• Deuterium in 3I/ATLAS ices is over 10 times higher than in solar system comets
• Carbon isotopic ratios fall outside the range of any measured body
• The ices formed 10–12 billion years ago, before the Sun
• 3I/ATLAS is the third confirmed interstellar object after 'Oumuamua and Borisov