This image has been bugging me this afternoon:

Here's an excerpt at 100% to illustrate what I mean:

I don't think it's electronic noise, because that's either evenly-distributed single pixels ("snow") or, if it's interference from a signal in the rover electronics, it would interact with the readout frequency of the CCD to produce a distinct regular pattern ("herringbone" for example).

Looks like a cloud chamber pattern, doesn't it? That's not to say it's a burst of hard radiation, but it could be lots of stray high-energy photons getting through the filter and impacting the sensor. Getting through the filter means their wavelength is near 880nm, middle infrared. OK, so it's photons and not a camera/electronics glitch. Then what in that scene is radiating random little bursts of infrared-grade photons? What's "sparkling"?

The image was taken at 9:20 in the morning, which I'm pretty sure is after sunrise; so I think that rules out a long-duration nighttime shot simply accumulating too many photons. At 9:23 the camera took another image containing a few multi-pixel dots on a light-grey background, but no streaks, looking like an early-morning-sky shot. The light might've been dim at the site, but it wasn't dark (I think). The only other right-camera images release on sol 80 are sundial images, and they don't show the "noise".

So what's going on in this image? Anybody got any ideas?