The Curiosity rover on Mars imaged some unusual events the other day. Here's the link to the NASA press release.
I've spent quite a bit of time over the years looking at Mars images. I don't recall ever seeing a cosmic ray event on any Mars images, although they clearly should happen very very often (my own experience with astronomical imaging tells me this). Perhaps since these cameras are "hardened" for space, they block most cosmic ray events? I find that theory doubtful. The NASA people say that cosmic ray events appear on images "nearly every week" but as I said I don't ever remember seeing one.
So I have a hard time with the cosmic ray explanation.
I also can't be too sure about the "glint" theory. Only one of the navcams saw this (the right one). The left navcam image, taken at the same time, shows nothing unusual. Check it out yourself at http://mars.jpl.nasa.gov/msl/multimedia/raw/ Left/Right Navigation Camera, Sol 559, timetag 2014-04-03 10:00:03 UTC. The earlier one is Sol 558, timetag 2014-04-02 09:04:28 UTC. Same thing: right navcam shows the event, left doesn't.
I have no theory as to what this is. I make two additional observations:
Obs 1: These events are 24h 55m 35s apart. A "solar day" on Mars is 24h 39m 35s. A close correlation.
Obs 2: Looking at the two images and blinking between them, it seems to me that whatever it is, it's in the same location on the surface in both images.
However, I can't come up with an explanation as to why a glint would appear in one camera and not in the other. Cosmic rays could, however. But as I said above, I would think that cosmic rays would be filtered out during calibration. Then to have two in as many days doesn't seem likely.
I think they should turn around and take a closer look. They have 30+ years of power, so why not? That rover should live up to it's name and here's a perfect chance to do so.