Astronomy Today@astronomytodayObservations of 37 nearby dwarf galaxies with Hubble found they kept only about 11% of the oxygen their stars had made, leaving roughly 89% of it unaccounted for.
Researchers suspect powerful stellar explosions drive gas out in galactic winds, which appear to strip oxygen from small galaxies far more effectively than models had predicted, since their weak gravity struggles to hold on to material.
Where the missing oxygen went is still unknown, though it may linger in the gas around galaxies or have travelled farther out.
