Because the H2 only comprises 1/9 of the mass of those products, the upper limit to micrometeoroid-delivered H2 is 0.04 g s−1. This upper limit is quite small in comparison to the source rate needed to reproduce the observations using an impact release mechanism of 25 g s−1. Even micrometeoroids comprised purely of water ice would not suffice. Direct delivery of H2 via micrometeoroids is not likely the source of the observed H2.