Listening for the Landing: Seismic Detections of Perseverance's Arrival at Mars With InSight

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 by the InSight lander (3,452 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 shock wave 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 by InSight. The upper and lower bounds on predicted ground velocity at InSight are 2.0 x 10(-14) and 1.3 x 10(-10) m s(-1). The upper value is above the noise floor at the time of landing 40% of the time on average. The large range of possible values reflects uncertainties in the current understanding of impact-generated seismic waves and their subsequent propagation and attenuation through Mars. 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 enormous value in constraining the seismic properties of Mars, and in improving our understanding of impact-generated seismic waves. Plain Language Summary When it lands on Mars, NASA's Perseverance Rover will have to slow down rapidly to achieve a safe landing. In doing this, it will produce a sonic boom and eject two large balance masses which will hit the surface at very high speed. The sonic boom and balance mass impacts will produce seismic waves which will travel away from Perseverance's landing site. Here, we evaluate whether these seismic waves will be detectable by instruments on the InSight lander (3,452 km away). We predict that the waves from the balance mass impacts may be detectable. If the waves are recorded by InSight, this would represent the first detection of ground motion generated by a seismic source on Mars at a known time and location. This would be of enormous value in advancing our understanding of the structure and properties of Mars' atmosphere and interior as well as in improving our understanding of how seismic waves are produced by meteorites hitting the surface.