D. W. Ming

TL;DR: Mössbauer spectra measured by the Opportunity rover revealed four mineralogical components in Meridiani Planum at Eagle crater: jarosite- and hematite-rich outcrop, hematITE-rich soil, olivine-bearing basaltic soil, and a pyroxene-bearing Basaltic rock (Bounce rock).

TL;DR: The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum, and the rocks are interpreted to be a mixture of chemical and siliciclastic sediments formed by episodic inundation by shallow surface water, followed by evaporation, exposure, and desiccation.

TL;DR: The analysis of the data from the Phoenix mission revealed an alkaline environment, in contrast to that found by the Mars Exploration Rovers, indicating that many different environments have existed on Mars.

TL;DR: The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater, but no clear evidence for lacustrine sedimentation has been found to date as discussed by the authors.

TL;DR: The Alpha Particle X-ray Spectrometer on the Opportunity rover determined major and minor elements of soils and rocks in Meridiani Planum, indicating the interaction with water in the past is indicated by the chemical features in rocks and soils.