re: DPS abstracts (yet more dry Mars). Yes, Mars seems dry now.
I'm sorry (a friend here once told me not to say that, but due to equivalent beliefs...), but I do believe that there was an ocean on mars and that led to rivers and deltas. There must have been an atmosphere to feed rain and everything else, even tectonics, that we know of that fed rivers and deltas to have caused these features on Mars for long periods... long periods before this planet that we call Mars announced it's death. Thankfully, the evidence is there, pockmarked by craters and all.