Even though scientists already knew about the existence of ice on Comet 67P/Churyumov-Gerasimenko — the same comet that the Rosetta space probe has been tailing and observing since 2014 — scientists have finally confirmed there is frozen H20 right beneath the celestial object's surface.
Using data sets sent from the Rosetta's Visible and Infrared Thermal Imaging Spectrometer (VIRTIS), which is more or less an infrared detector, a team of scientists based at the National Institute for Astrophysics in Rome was able to determine the presence of grain-sized speckles of water ice on areas of 67P where bits of the comet's outer crust had broken off, leaving the frozen droplets exposed.
While the researchers, who published their results in the scientific journal Nature, determined that "the nucleus can develop an extended and complex coating in which the outer dehydrated crust is superimposed on layers enriched in water ice," it is still unclear as to how the ice actually formed there in the first place.
However, there are theories: as Physics points out, the smaller grain-like formations might have to do with frost formations that occur as the comet "rotates," or faces away from the sun, and condensation goes from being in hot temperatures to cold.
As for the larger micrometer-range drops? It's still anyone's guess.
What the results do mean is that now scientists have a better idea of not only where water exists on or beneath the comet's surface, but how much.
"We knew water ice made up the majority of the comet, but we didn't know how deep or in what condition it was," said Murthy Gudipati, one of the leading scientists of the study, in an interview with Physics. "This shows that it not very deep at all, perhaps just a few feet beneath the surface."
Learn more about Comet 67P, Rosetta and its probe Philae in the video below.