It could be the first time we've ever discovered interstellar water in our own Solar System.
Astronomers from NASA's Goddard Space Flight Center believe the recently discovered interstellar object 2I/Borisov may hold water, New Scientist reports.
While we've previously detected water in the atmospheres of interstellar exoplanets, this could mark the first time we've located water originating from a different planetary system within our own solar system.
Using the Apache Point Observatory in New Mexico, a team led by astronomer Adam McKay found that Borisov, believed to be an interstellar comet, seems to be giving off large amounts of oxygen.
They believe the gas could be the result of UV rays from the Sun splitting water vapor into hydrogen and oxygen atoms.
2I/Borisov was discovered in August and is only a couple kilometers across. Its odd trajectory and extreme velocity led astronomers to conclude it came from another distant star system — despite it looking "remarkably like a normal Solar System comet," as astronomer Colin Snodgrass from the University of Edinburgh told Science.
Finding evidence of interstellar water this close to home —relatively speaking — could provide new insight into the nature of other distant star systems. It could even have implications for the existence of alien life.
"Are we special as a planetary system or are a lot of planetary systems like ours?" McKay told New Scientist. "That has implications for the origin of life, and how common life is throughout the universe."
READ MORE: Alien water may have been found on interstellar comet Borisov [New Scientist]
More on alien life: Former NASA Scientist “Convinced” We Already Found Life on Mars