Wow, thank you for such a informative response. I know that in any field high precision and accuracy generally are very expensive (something about the first 90% being cheap, and the last 10% ...), so I expected it would be a complex process - especially given the hyper-constrained resources on Mars. But wow - sounds fun.
HN is not the usual audience, of course; most people don't think to ask the question. And of course, maybe others republish the images without noting the alterations. And it seems my criticism/question is outdated, as you say NASA has made more effort to address this issue.
> Nobody would seriously contemplate putting some kind of interpretive warning on such images, because we all know you can't see water vapor or ocean salinity directly.
It's hard to for experts to underestimate what 'we all know' (I and my peers have the same problem in my field - look at what HN users think typical computer users know, can grasp, and will do); looking at that map[0] I could easily imagine many people thinking it was somehow real. Here's a recent story, no exaggeration: I was watching a sports commentary show widely praised as among the most intelligent, and they had on a guest who revealed that he had studied astrophysics in a prior life. One of the commentators asked (and I'm paraphrasing, but this was really the question):
Maybe you can settle a argument for (another commentator) and me: What is further from New York, Los Angeles or the Moon? Because I can see the Moon from New York, but I can't see Los Angeles.
HN is not the usual audience, of course; most people don't think to ask the question. And of course, maybe others republish the images without noting the alterations. And it seems my criticism/question is outdated, as you say NASA has made more effort to address this issue.
> Nobody would seriously contemplate putting some kind of interpretive warning on such images, because we all know you can't see water vapor or ocean salinity directly.
It's hard to for experts to underestimate what 'we all know' (I and my peers have the same problem in my field - look at what HN users think typical computer users know, can grasp, and will do); looking at that map[0] I could easily imagine many people thinking it was somehow real. Here's a recent story, no exaggeration: I was watching a sports commentary show widely praised as among the most intelligent, and they had on a guest who revealed that he had studied astrophysics in a prior life. One of the commentators asked (and I'm paraphrasing, but this was really the question):
Maybe you can settle a argument for (another commentator) and me: What is further from New York, Los Angeles or the Moon? Because I can see the Moon from New York, but I can't see Los Angeles.
[0[ https://www.jpl.nasa.gov/spaceimages/details.php?id=pia21209