A shocking new study suggests that the second interstellar object ever discovered, Comet 2I/Borisov, could be carrying water on it from beyond the Solar System.
The study suggests that 2I/Borisov, discovered on Aug. 30 by astronomer Gennady Borisov, is releasing water vapor on its journey.
“Using a simple sublimation model we estimate an H2O active area of 1.7 km2 [0.65 miles squared], which for current estimates for the size of Borisov suggests active fractions between 1-150 [percent], consistent with values measured in Solar System comets,” the study’s abstract states. It is common for asteroids in the Solar System to carry water.