Below is a table of the discoveries and the implications. The isomer HNC is unstable, and the ratio is consistent with interstellar cloud origin. Abuncance is 0.25. Abundance is 0.5. However, the interpretation of these observations is being contested.
Isotopic ratio is compatible with values seen on Earth.
First secure detection in a comet. C 2 H 2 CH 3 OH Methane Acetelyne Methanol 1.124 Mumma et al. The molecule does not originate primarily from the nucleus. Abundance is 50 times lower than for the related molecule, methanol. IAU Circular No.