Impact-Seismic Investigations of the InSight Mission - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Space Science Reviews Année : 2018

Impact-Seismic Investigations of the InSight Mission

Ingrid Daubar
Nicholas A. Teanby
  • Fonction : Auteur
Katarina Miljkovic
  • Fonction : Auteur
Jennifer Stevanović
  • Fonction : Auteur
Balthasar Kenda
Taichi Kawamura
John Clinton
  • Fonction : Auteur
Antoine Lucas
Melanie Drilleau
Gareth S. Collins
  • Fonction : Auteur
Don Banfield
Matthew Golombek
Sharon Kedar
  • Fonction : Auteur
Nicholas Schmerr
Tamara Gudkova
  • Fonction : Auteur
Maria Banks
  • Fonction : Auteur
Justin Maki
Eleanor Sansom
  • Fonction : Auteur
Mark Panning
Nobuaki Fuji
James Wookey
  • Fonction : Auteur
Martin van Driel
  • Fonction : Auteur
Mark Lemmon
Maren Böse
Simon Stähler
Hiroo Kanamori
  • Fonction : Auteur
James Richardson
  • Fonction : Auteur
Suzanne Smrekar
W. Bruce Banerdt
  • Fonction : Auteur

Résumé

Abstract Impact investigations will be an important aspect of the InSight mission. One of the scientific goals of the mission is a measurement of the current impact rate at Mars. Impacts will additionally inform the major goal of investigating the interior structure of Mars. In this paper, we review the current state of knowledge about seismic signals from impacts on the Earth, Moon, and laboratory experiments. We describe the generalized physical models that can be used to explain these signals. A discussion of the appropriate source timefunction for impacts is presented, along with spectral characteristics including the cutoff frequency and its dependence on impact momentum. Estimates of the seismic efficiency (ratio between seismic and impact energies) vary widely. Our preferred value for the seismic efficiency at Mars is 5 × 10−4 , which we recommend using until we can measure it during the InSight mission, when seismic moments are not used directly. Effects of the material properties at the impact point and at the seismometer location are considered. We also discuss theprocesses by which airbursts and acoustic waves emanate from bolides, and the feasibility of detecting such signals. We then consider the case of impacts on Mars. A review is given of the current knowledge of present-day cratering on Mars: the current impact rate, characteristics of those impactors such as velocity and directions, and the morphologies of the craters those impactors create. Several methods of scaling crater size to impact energy are presented. The Martian atmosphere, although thin, will cause fragmentation of impactors, with implications for the resulting seismic signals. We also benchmark several different seismic modeling codes to be used in analysis of impact detections, and those codes are used to explore the seismic amplitude of impact-induced signals as a function of distance from the impact site. We predict a measurement of the current impact flux will be possible within the timeframe of the prime mission (one Mars year) with the detection of ∼ a few to several tens of impacts. However, the error bars on these predictions are large. Specific to the InSight mission, we list discriminators of seismic signals from impacts that will be used to distinguish them from marsquakes. We describe the role of the InSight Impacts Science Theme Group during mission operations, including a plan for possible night-time meteor imaging. The impacts detected by these methods during the InSight mission will be used to improve interior structure models, measure the seismic efficiency, and calculate the size frequency distribution of current impacts.

Domaines

Autre
Fichier principal
Vignette du fichier
Daubar_21693.pdf (9.44 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01990992 , version 1 (23-01-2019)

Identifiants

Citer

Ingrid Daubar, Philippe Lognonné, Nicholas A. Teanby, Katarina Miljkovic, Jennifer Stevanović, et al.. Impact-Seismic Investigations of the InSight Mission. Space Science Reviews, 2018, 214 (132), pp.1-68. ⟨10.1007/s11214-018-0562-x⟩. ⟨hal-01990992⟩
296 Consultations
101 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More