A new paper published in Nature Astronomy says that "Oumuamua might have a frozen heart, encased in a soft coat of carbon-rich gunk soft enough to sink under your boots". Scientists suspect that the dark red material is likely made from organic ices which have been broken down after millions of years of cosmic radiation, and is robust enough to protect the object's cold interior.

But exactly what's going on inside Oumuamua will remain a mystery, since it's now blasting away from our solar system. Speaking to Popular Science, the paper's lead author Alex Fitzsimmons said: "Is there really water ice inside? What is the interior structure really like? We'll probably never know for sure with Oumuamua, but another one will be spotted at some point in the future. Hopefully we will have more time to study the next one."