Herschel has found the first robust evidence of molecular oxygen in the Orion Nebula. The observed abundance is ten times larger than indicated by previous observations of other molecular clouds, but is still well below theoretical expectations. The results suggest that, in special circumstances, the heat from newborn stars can liberate oxygen frozen out on dust grains, thus increasing the amount of molecular oxygen able to form in warm, dense gas clouds…
ESA Science & Technology: Herschel uncovers ‘hidden’ oxygen in Orion