Geology of the InSight landing site on Mars.

The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) spacecraft landed successfully on Mars and imaged the surface to characterize the surficial geology. Here we report on the geology and subsurface structure of the landing site to aid in situ geophysical investigations. InSight landed in a degraded impact crater in Elysium Planitia on a smooth sandy, granule- and pebble-rich surface with few rocks. Superposed impact craters are common and eolian bedforms are sparse. During landing, pulsed retrorockets modified the surface to reveal a near surface stratigraphy of surficial dust, over thin unconsolidated sand, underlain by a variable thickness duricrust, with poorly sorted, unconsolidated sand with rocks beneath. Impact, eolian, and mass wasting processes have dominantly modified the surface. Surface observations are consistent with expectations made from remote sensing data prior to landing indicating a surface composed of an impact-fragmented regolith overlying basaltic lava flows.

Ipsilateral radial-head dislocation and distal fractures of both forearm bones in a child.

Monteggia's fracture-dislocation is a common fracture pattern seen in children. In this case report, an unusual injury pattern, consisting of a dislocation of the radial head with ipsilateral fractures of the distal radius and ulna, is described. This fracture-dislocation may represent a variation of Monteggia's lesion.