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Updated: Jul 18, 2026

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM
Published on: September 27, 2017
Evidence from Opportunity's Microscopic Imager for water on Meridiani Planum
K E Herkenhoff1, S W Squyres, R Arvidson
1U.S. Geological Survey Astrogeology Team, Flagstaff, AZ 86001, USA. kherkenhoff@usgs.gov
Abstract:
The Microscopic Imager on the Opportunity rover analyzed textures of soils and rocks at Meridiani Planum at a scale of 31 micrometers per pixel. The uppermost millimeter of some soils is weakly cemented, whereas other soils show little evidence of cohesion. Rock outcrops are laminated on a millimeter scale; image mosaics of cross-stratification suggest that some sediments were deposited by flowing water. Vugs in some outcrop faces are probably molds formed by dissolution of relatively soluble minerals during diagenesis. Microscopic images support the hypothesis that hematite-rich spherules observed in outcrops and soils also formed diagenetically as concretions.
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