Table 1. Timeline Showing Detection of Aqueous Minerals by Different Mars Orbital Spectroscopic Investigationsa

	MGS TES	MEx/OMEGA	Odyssey THEMIS	MRO/CRISM, MRO/HiRISE
Spatial resolution	6 km/pixel	0.3-2 km/pixel	18 m/pixel VIS, 100 m/pixel IR	18 m/pixel CRISM VISIR, 0.3 m/pixel HiRISE VIS
Wavelength	6-50 mum	0.4-5.1 mum	0.4-1.0, 6-15 mum	0.4-3.9 mum
Layered phyllosilicates		Al and Fe/Mg clays at Nili and Mawrth	-	Stratification of different compositions; detailed stratigraphy
Phyllosilicates in intercrater fans				Highland crater fans/deltas contain phyllosilicate-bearing layers
Plains sediments			Chloride detection	Cooccurrence with phyllosilicates in layers
Deep phyllosilicates		Unknown hydrated mineral in dozens of highland craters	-	> 5000 outcrops in craters, chasmata; chlorite + other hydrated silicates
Intracrater clay-sulfate deposits				Sulfates and interbedded clays in highland craters
Carbonate deposits				Thin layers of hydrous carbonates on olivine-rich rocks
Meridiani-type layered deposits	Deposits of gray hematite	Adjacent occurrences of monohydrated and polyhydrated sulfates	-	Improved resolution of largely undeformed vertical stratification
Valles-type layered deposits	Deposits of gray hematite	Adjacent occurrences of monohydrated and polyhydrated sulfates	-	Intricate vertical layering of sulfate types and Fe oxides; folding; alteration zones
Siliceous layered deposits				Widespread hydrated silica in layered deposits on Hesperian plains
Gypsum plains		Gypsum-rich optical surface	-	Relationship to basal unit


aAs spatial resolution and wavelength coverage of the data have improved, the diversity of recognized deposits and their known spatial distributions have increased. Data are given for the time during which a class of deposits' existence was known. Hyphens mean there are no new mineral identifications.