Abstract
<title>Abstract</title> <p>We searched the Mars InSight seismic data for signals that would indicate the presence of an inner core, such as the inner-core boundary-reflecting phase, PKiKP, and the bottom-side outer-core-reflection, PKIKKIKP. For this, we analysed the highest-quality events from the seismically most active region (Cerberus Fossae) detected on Mars. Using source-array methods, we compute vespagrams and associated F-vespagrams, wherein a strong energy peak at a specific time and horizontal slowness indicates a coherent seismic phase. We validated our method on body wave phases seen earlier by the InSight team, such as SS. Application to PKiKP and PKIKKIKP produces coherent signals for a range of candidate inner-core radii, specifically 200–300 km and 500–600 km for PKiKP and 100--600~km for PKIKKIKP. This suggests that the interpretation of inner-core seismic signals is not unique and, consequently, there is no definitive evidence confirming the existence of an inner core on Mars.</p>