X-ray Spectrometer". Science. 306. 1746-1749. https://doi.org/10.1126/science.1104358Bell, J. F., III, et al. (2004), Pancam multispectral imaging results from the Opportunity Rover at Meridiani Planum, Science, 306(5702), 1703–1709. https://doi.org/10.1126/science.1105245. Squyres, S.W., Grotzinger, J.P., Arvidson, R.E., Bell, J.F., Calvin, W., Christensen, P.R., et al., 2004, "In Situ Evidence for an Ancient Aqueous Environment at Meridiani Planum, Mars." Science, 306 ( 5702), pp. 1709-1714. https://doi.org/10.1126/science.1104559 These tests included doing the "berry bowl" experiment (more below). The moniker "blueberries" was coined for the grey hematite spherules by the original Opportunity science team due to these spherules appearing bluish relative to the underlying rusty-red soils in the "natural color RGB images" analyzed. Blueberry Formation Blueberries are either embedded in the large body of sediments of Meridiani Planum or they are loose blueberries that lie directly on outcrops of the sediments or lie on top soils spread over the Meridiani sediments.Grotzinger, J. P., Arvidson, R. E., Bell III, J. F., Calvin, W., Clark, B. C., Fike, D. A. et al. (2005). "Stratigraphy and sedimentology of a dry to wet eolian depositional system, Burns formation, Meridiani Planum, Mars." Earth and Planetary Sci. Let., 240, 11 – 72. https://doi.org/10.1016/j.epsl.2005.09.039 The loose blueberries and soils are eroded out of the underlying sediments. Both today's embedded blueberries and the loose blueberries were formed in the sediments of Meridiani Planum by "diagenetic" processes, i.e., processes that change sediments by water-rock interactions.Arvidson, R. E., Poulet, F., Morris, R. V., Bibring, J.-P., Bell III, J. F., Squyres, S. W., et al., 2006, "Nature and origin of the hematite-bearing plains of Terra Meridiani based on analyses of orbital and Mars Exploration rover data sets," J. GeoPhys. Res.; Planets, 111, E12S08. https://doi.org//10.1029/2006JE002728 The diagenetic processes not only formed embedded blueberries but also changed an original large body of sediments. Thus, blueberry formation was (broadly) a three-step process: Formation of the original body of sediments; Diagenetic transformation of the original sediments to produce today's sediments and embedded blueberries; Erosion of top layers of the sediments to form top soils and loose blueberries. Each of these broad steps involved multiple sub-step processes, described in the following sub-sections: Noachian River Flows Prior to the formation of Meridiani's defining sediments, in the wet Noachian (named for the biblical Noah) more than about ~3.7 billion years ago, liquid water was present and plentiful enough to form river channels that bought and deposited large quantities of basaltic silt to the current Meridiani