Skip to Main content Skip to Navigation
Journal articles

A New Crater Near InSight: Implications for Seismic Impact Detectability on Mars

Abstract : A new 1.5 m diameter impact crater was discovered on Mars only ~40 km from the InSight lander. Context camera images constrained its formation between 21 February and 6 April 2019; follow-up High Resolution Imaging Science Experiment images resolved the crater. During this time period, three seismic events were identified in InSight data. We derive expected seismic signal characteristics and use them to evaluate each of the seismic events. However, none of them can definitively be associated with this source. Atmospheric perturbations are generally expected to be generated during impacts; however, in this case, no signal could be identified as related to the known impact. Using scaling relationships based on the terrestrial and lunar analogs and numerical modeling, we predict the amplitude, peak frequency, and duration of the seismic signal that would have emanated from this impact. The predicted amplitude falls near the lowest levels of the measured seismometer noise for the predicted frequency. Hence, it is not surprising this impact event was not positively identified in the seismic data. Finding this crater was a lucky event as its formation this close to InSight has a probability of only ~0.2, and the odds of capturing it in before and after images are extremely low. We revisit impact-seismic discriminators in light of real experience with a seismometer on the Martian surface. Using measured noise of the instrument, we revise our previous prediction of seismic impact detections downward, from ~a few to tens, to just ~2 per Earth year, still with an order of magnitude uncertainty.
Complete list of metadata

https://hal-univ-paris.archives-ouvertes.fr/hal-03657967
Contributor : Sébastien Rodriguez Connect in order to contact the contributor
Submitted on : Tuesday, May 3, 2022 - 2:25:21 PM
Last modification on : Friday, August 5, 2022 - 12:01:25 PM
Long-term archiving on: : Thursday, August 4, 2022 - 6:35:25 PM

File

2020_Daubar_JGR_A New Crater N...
Publisher files allowed on an open archive

Identifiers

Citation

I Daubar, P Lognonné, N Teanby, G Collins, J Clinton, et al.. A New Crater Near InSight: Implications for Seismic Impact Detectability on Mars. Journal of Geophysical Research. Planets, Wiley-Blackwell, 2020, 125 (8), pp.e2020JE006382. ⟨10.1029/2020je006382⟩. ⟨hal-03657967⟩

Share

Metrics

Record views

12

Files downloads

6