Abstract Low frequency sound can travel great distances in planetary atmospheres. When these waves reflect off the air/ground interface, energy may be absorbed or transferred to mechanical waves in the subsurface. This study describes the direct and reflected acoustic wave generated by the re‐entry of the OSIRIS‐REx Sample Return Capsule captured on a pair of balloon‐borne recorders. Reflection attenuation at high incidence angles on alluvium deposits are minimal below 10 Hz. Frequency‐dependent ground absorption between 10 and 50 Hz was evident on a low‐floating platform, but masked by atmospheric attenuation and nonlinear wave propagation at higher altitudes. These results bridge the gap between near‐lossless reflection assumed by infrasound studies and frequency‐dependent losses noted in the low audio range.
Bowman et al. (2026) studied this question.