From https://www.almaobservatory.org/en/press-release/alma-reveals-unusual-composition-of-interstellar-comet-2i-borisov/ https://www.almaobservatory.org/en/pres

From https://www.almaobservatory.org/en/press-release/alma-reveals-unusual-composition-of-interstellar-comet-2i-borisov/ https://www.almaobservatory.org/en/press-release/alma-reveal...: "the concentration of CO is higher than anyone has detected in any comet within 2 astronomical units (au) from the Sun,”suggesting that “the comet must have formed from material very rich in CO ice, which is only present at the lowest temperatures found in space, below -420 degrees Fahrenheit (-250 degrees Celsius). [...] If the gases we observed reflect the composition of 2I/Borisov’s birthplace, then it shows that it may have formed in a different way than our own solar system comets, in an extremely cold, outer region of a distant planetary system."