Astronomers using radio telescope observations to get an inside look at an interstellar comet have gleaned new insights into when and where the celestial object formed.The comet, named 3I/ATLAS, gained global attention when researchers first discovered it zipping through our solar system in July. It’s only the third interstellar object, or celestial body that originated outside our solar system, to be spotted passing through our corner of the universe. The comet began its exit of our solar system in December.Initial research about the comet’s composition, published April 23 in the journal Nature Astronomy, shows that it originated somewhere very different from our own solar system, according to the study authors.AdvertisementAdvertisementThe observations were made using the Atacama Large Millimeter/submillimeter Array, or ALMA, in Chile in early November, just days after the comet passed closest to our sun.The ALMA radio telescope enabled researchers to measure deuterium within the comet, marking the first time this isotope of hydrogen has been detected in an interstellar object.“Deuterium is generally found in the water of Solar System comets and in Earth’s oceans in the form of deuterated water, HDO, also called semi-heavy water,” lead study author Luis Eduardo Salazar Manzano, a doctoral candidate in the department of astronomy at the University of Michigan, wrote in an email.“Our observations with ALMA indicate that the abundance of deuterium in the water of 3I/ATLAS is more than 40 times the value in Earth’s oceans and more than 30 times the value in Solar System comets.”AdvertisementAdvertisementThe findings may allow researchers to better understand the extreme conditions of the comet’s planetary system — and even discern what the Milky Way galaxy was like long before our solar system appeared.“Interstellar objects are time capsules that bring material from the environments where other planetary systems formed, and our measurements are finally allowing us to open those time capsules and peek at the physical conditions where these objects originated,” Salazar Manzano said.A graphic compares the semi-heavy water content of 3I/ATLAS (left) and Earth. – NSF/AUI/NSF NRAO/M.Weiss/[email protected]/NSF/AUI/NSF NRAO/M.WeissAn ancient and unusual objectWater, or H2O, typically contains two hydroge …
