Interstellar Comet: Water 14 Times Heavier Than Earth's ⚡ экспресс
With the help of the James Webb Telescope, the composition of the coma of interstellar object 3I/ATLAS was studied for the first time. It was found that the deuterium-to-hydrogen ratio (D/H) in methane is (3.31±0.34)%, which is 14 times higher than that of comet Churyumov-Gerasimenko. This is a rare case of detection of deuterated organic molecules in an interstellar wanderer. The high content of heavy hydrogen indicates that the object was born in a very cold environment of a protoplanetary disk of a distant star. Thus, 3I/ATLAS becomes a key to understanding the chemistry of other worlds.
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.
For 3I/ATLAS, this 'thermometer' is off the charts: for every 30 ordinary hydrogen atoms, there's one deuterium atom—in Earth's oceans, that ratio is hundreds of times poorer. This means the comet was born in the icy darkness of a distant protoplanetary disk—a region where planets are just beginning to coalesce from cosmic dust and gas. This alien world is far colder than the cloud that gave birth to our Sun and Earth.
🎯 The deuterium abundance points to a comet birth temperature below –250°C — colder than the eternal shadows on the Moon.
🎬 Interstellar wanderers like 3I/ATLAS come to life in the pages of science fiction: for example, in Arthur C. Clarke's novel 'Rendezvous with Rama'.