I put the shape down to either one of the moons, or one of the orbiters (either one of the ones that dropped the rovers, or one from an older mars
mission).
What I was mainly referring to was the "cleaning" of the rovers:
We both had an increased interest in the Mars expedition, since NASA announced in a press release last week that something or someone had been
cleaning the dust off the solar cells at night on the Mars Rover Vehicle Opportunity vehicle (yes same one that took the UFO picture!) nobody can
explain the apparently nightly washing. The regular cleaning had been increasing the efficiency from like 40 or 50% to almost 100%. Just enough to get
the picture?
Sounds weird to say the least, but it may have been cleaned by unusual wind gusts? The other rover was reportedly at around 40-50% efficiency, while
after each night "Opportunity" was giving almost 100%
The cleaning had boosted the panels' power output close to their maximum 900 watt-hours per day after at one stage dropping to 500 watt-hours
because of the heavy Martian dirt.
By contrast, the power output of the solar panels of Mars Spirit -- on a different part of the Red Planet -- had dropped to just 400 watt-hours a day,
clogged by the heavy dust.
