Listening for the Landing: Detecting Perseverance’s landing with InSight

Benjamin Fernando , Natalia Wójcicka, Marouchka Froment, Ross Maguire, Simon Staehler, Lucie Rolland, Gareth Collins, Ozgur Karatekin, Carene Larmat, Eleanor Sansom, Nicholas Teanby, Aymeric Spiga, Foivos Karakostas, Kuangdai Leng, Tarje Nissen-Meyer, Taichi Kawamura, Domenico Giardini, Philippe lognonne, Bruce Banerdt, Ingrid J Daubar

The entry, descent, and landing (EDL) sequence of NASA's Mars 2020 Perseverance rover will act as a seismic source of known temporal and spatial localization. We evaluate whether the signals produced by this event will be detectable at the InSight lander (3452~km away), comparing expected signal amplitudes to noise levels at the instrument. Modeling is undertaken to predict the propagation of the acoustic signal (purely in the atmosphere), the seismoacoustic signal (atmosphere-to-ground coupled), and the elastodynamic seismic signal (in the ground only). Our results suggest that the acoustic and seismoacoustic signals, produced by the atmospheric shockwave from the EDL, are unlikely to be detectable due to the pattern of winds in the martian atmosphere and the weak air-to-ground coupling, respectively. However, the elastodynamic seismic signal produced by the impact of the spacecraft's cruise balance masses on the surface may be detected at InSight. The upper and lower bounds on predicted ground velocity at InSight are $1.0\times 10^{-14}$~ms$^{-1}$ and $1.3\times 10^{-10}$~ms$^{-1}$. The upper value is above the average noise floor at the time of landing 45\% of the time. The uncertainties on this value reflect uncertainties in the current understanding of impact processes and translation of these into seismic signals. Uncertainty in the detectability also stems from the indeterminate instrument noise level at the time of this future event. A positive detection would be of great value in constraining the properties of the martian crust and mantle as well as in improving our understanding of impact-generated seismic waves.