Down in that thread about Hoagland's "Tides of Mars" paper, I mentioned that he cites an investigation by Jill England and Efram Palermo into those dark streaks on Mars that have intrigued quite a few people, most noticeably our own Dan Spires. England & Palermo presented a paper at the 4th Annual Mars Society Convention with the unwieldy title "A Study of Mars Global Surveyor (MGS) Images Showing Probable Water Seepages. Are They Dust Slides as NASA CLaims or Proof of Water on Mars?" (whew!). The paper's online at http://www.users.qwest.net/~vtwild/webpage/Mars%20Society%20Seeps%20Paper.pdf.

I should make clear that while Hoagland's "Tides of Mars" theory was inspired in part by England & Palermo's study, the reverse is not true--their study doesn't depend on "Tides of Mars". They seem to have executed the technical part pretty well. Jill England is evidently a database "goddess", and her analysis of the geographic distribution and frequency of the stains looks solid. The images were handled well, which is important to their observations about the different shades of overlapping stains as, they assert, evidence for successive flows.

It's the conclusions they draw that I expect to be controversial. Do they really make a case for water flow as the cause of the stains?

--Robert