The detection of ethylene (C₂H₄) was reported by Betz in 1981 in IRC+10216. In contrast to most identifications made to date, ethylene was identified by means of infrared rather than mm or sub-mm spectroscopy. Two lines of the ν₇ band were observed with the McMath Solar Telescope at Kitt Peak. Seven additional lines were reported in 1987 by Goldhaber et al. Ethylene has also been detected in several solar system bodies, including Jupiter, Saturn and its moon Titan, and Neptune.

Ethylene (also known as ethene) is the smallest stable hydrocarbon with a carbon-carbon double bond. It is widely used in the chemical industry, particularly as a feedstock in the production of other chemicals, including polyethylene and polystyrene, but is also produced in nature and is part of the ripening process in many fruits.