Alien object 'Oumuama was a natural body visiting from another solar system
phys.org
phys.org
"Oumuamua is similar to small solar system bodies that are covered in carbon-rich ices,
whose structure is modified by exposure to cosmic rays."
Wich indicates, that carbon is pretty abundant, not just in our solar system, but elsewhere too. This is also not completely new[1], but the first time we had a close encounter with a carbon-rich object that did't originate in our solar system.[1]: http://www.astronomy.com/News-Observing/News/2009/11/Carbon%...