Post by chrlz on Jan 13, 2012 20:48:49 GMT -4
But the rover tracks are visible in many LRO pictures with that same resolution. I think it has more to do with the illumination angle and the angle with which LRO is viewing the scene (not always straight down). Already I've noticed many Apollo artifacts that are very prominent in some LRO pictures and completely invisible in others.
And of course the same applies to many natural features like craters, which become almost invisible at high sun angles when there are no shadows to reveal their topography.
Very true, and I admit my post was rather dismissive (it's hard not to be when Jarrah's deliberate bulldung is in question..).
Jarrah and his ilk always like to try to reduce their claims down to ludicrously simplistic one liners (that are usually incorrect in their own right anyway!).
Whether or not a rover (or astronaut) track is visible depends on a myriad of issues, eg:
- the actual resolution of the camera (which may not be the same as the theoretical one)
- the angle of the lighting relative to the track & topography
- the length and nature of the track and the angle with which it aligns with the camera sensor array
- whether the track has a different texture relative to the surrounding regolith and if that affects the resolvability
- whether the creation of the track uncovered regolith of a different colour/reflectiveness
For anyone like Jarrah, it is easy to see these effects in action here on Earth. Use Google Earth to examine some beaches and parks in your area (remembering of course that much of GE imagery is of significantly higher resolution than the LRO is capable of) and then look at areas that you *know* would have tracks of various types at the time they were photographed. How many are visible .. and why?