A rough idea of what was (and was not) known is Greeley's Mars landing site catalog (1990). See http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900018291.pdf Note that Mangala (which isn't considered that exciting now) gets no less than three mentions (sites 27, 38 and 39).
Quote from: Dalhousie on 02/21/2015 06:12 amA rough idea of what was (and was not) known is Greeley's Mars landing site catalog (1990). See http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900018291.pdf Note that Mangala (which isn't considered that exciting now) gets no less than three mentions (sites 27, 38 and 39). And it loks as if Mangala valles was considered as a potential landing site for Mars Surveyor 2001 (Mars Polar Lander ill-fated twin brother that was stored in 2000 and later returned as Phoenix in 2007). Mangala unfortunately was not selected (anyway, Dalhousie, why isn't Mangala considered exciting nowadays ?) http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20000112986.pdf
...Mangala was chosen because it is an outflow channel and studying it would give us an idea about the history of liquid water on Mars. Much the same reasoning was chosen for the Ares Vallis landing site for Mars Pathfinder in 1996.
Talking with Mike last night, I am assuming the Mariner sent to Mars in the 1975 Viking window would basically have the same resolution as the Viking orbiter. It concentrated on equatorial areas for landings sites. So, if you want to see what York and NASA knew of Mars before they went, look at those photos. It is also possible they got photos from the Soviets.But York wanted Mangala, she was part of the team that chose it. And she influenced the choice.(I almost feel like this actually happened, the more we discuss it!)
Quote from: Dalhousie on 02/23/2015 08:08 am...Mangala was chosen because it is an outflow channel and studying it would give us an idea about the history of liquid water on Mars. Much the same reasoning was chosen for the Ares Vallis landing site for Mars Pathfinder in 1996.And, just as an aside, the same reasoning also applied to the selection of the Chryse landing site for the Viking 1 lander. The Chryse and Ares Vallis outflow channels are related -- if you look closely at the maps, you can convince yourself that both were made by the same catastrophic flood event. Separate lobes of the catastrophic flood waters, so to speak.