You guys are torturing me! I actually didn't have much energy around the Water Question, because there was so much evidence pointing that way anyway; but I do really really want to find microfossils!

Yet I know from lots of past experience with interpreting images of Mars how easy it is to let one's hopes bias perception. Shapes are a mental minefield, as the Rorschach Test illustrates. Now, imagine a Rorschach Test in which the subject gets to fiddle with the ink blots to "enhance" them--you can bet the subject will make the shapes look more like whatever his/her subconscious wanted them to be in the first place.

That's why I feel afraid, very afraid, when you asked "is image enhancement possible?" Oh, yes, yes it is, and the thought of fiddling with an image to "bring out" the microfossils gives me the willies. So nope, I won't fiddle with that image at all.

However, there are other, safer ways to explore the question. Your second image of a (maybe) microshrimp (is that redundant?) was taken before the RAT ground into the rock at that spot. Here's the after:

(click for full-size)

If that were really a microfossil, then the RAT would have revealed it in cross-section. You can use the three spherules for landmarks; the "microshrimp" should be along a line from the lower-right to the upper-left spherule. I don't see anything.

I don't want to sound negative. I guess it's because this site is so promising already, having been determined to have been underwater, that I'm on the edge of my seat and sensitive to false alarms. At any moment we might actually see a microfossil.

And here's a mystery to heighten the tension: The status report for sol 37 says that Opportunity was grinding a rock, and PanCam images from the same day show the aftermath of a grinding. Yet there were no Microscopic Imager images released that sol. If you want to make yourself crazy, wonder why.