The loss of atmosphere from Mars - Response

The results presented in our report (1) indicated that it was necessary to consider dissociation during all collisions in calculating the atmospheric loss from Mars that results from sputtering. With the use of the newly calculated cross sections presented by Johnson and Liu in our model, we find that Mars has lost about 1 bar of CO_2. The revised cross sections reduce our sputtering yields (Table 1), but do not bring our results into agreement with Luhmann et al. (2) and Jakosky et al. (3).