Comet C/2016 R2 (Pan-STARRS)
C/2016 R2 is a solar system comet from the Oort Cloud distinguished by extraordinary carbon monoxide and ion-driven chemistry. It held the highest methanol-to-HCN ratio measured in any comet until 3I/ATLAS.
It became a test case for how comet chemistry varies with formation conditions.
It remains the sole local reference point for extreme methanol enrichment.
The only comet with a higher methanol-to-HCN ratio than 3I/ATLAS is this local oddball, sharpening the view that 3I/ATLAS formed under unusual conditions.
