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Happy Christmas Everyone...

Doug

The #1 clincher for me is the corners of the solar arrays. Comapre the vivid red and black features on Opportunity - and then the, essentially, butterscotch tinted versions there-of on Spirit. Yeah  - maybe different lighting conditions, but lighting doesnt shift contrast and colour that much

Doug

Can you guys really not see how the dust is clumped up into small areas on Opportunity - particularly around the PMA hold down bracket? I'm not seing things here - this is real stuff I'm talking about. I'm not trying to be stubourn or stupid - and I had my eyes tested only a few weeks ago so I know I'm not seing things. What has happene here couldnt be more obvious. Brutal, obvious, unmistakeable difference in colour between the two rovers - and a difference that corresponds very very well to a dustier surface on spirit, and a 'cleaned' surface on Opportunity.  I

Honestly - guys - cant you see it? This isnt some "oo - a rock that looks like a tank" type thing - this is verbose, obvious colour differences between two identical objects in similar lighting conditions.

I'm trying to be as scientific as I can here - but I see no need to be honest - the images tell the story so very very loudly!!

http://mer.rlproject.com/dust_move_waaa … waaaaa.jpg

Look at the are below the text - it's roughtly one average colour throughout - whereas with the opportunity image, there is a darker area, and some browner clumpy areas.  Can you not see how one can become the other?  Cant you see it?

I've brightened the Opportuity image a LOT - it's without doubt brighter than the spirit image - but look at the solar cells

Bluring it to eliminate noise - an Opportunity cell comes in at an RGB value of 73:103:77

Same process with Spirit produces 104:109:82.

If we take an average of all 6 values to make a grey value - it's 91

Surely you can see that the NEITHER are grey - and one is considerably more 'tan' than the other?   

Doug

Athena was never designed to do Met work. The volume, mass, power and data budget preclude it being included anyway.  Spot measurements are possible with Mini TES however

Doug

The first image is the most obvious one. If it were an exposure issue - then the Spirit solar arrays would perhaps be grey, instead of near-black - but they're not - they're very very very brown - other dark areas are less dark than they appear on Opportunity

Compare the colours of components such as the silver bracket the pyro-device for the PMA tie down was situated - it's very much the same shade in both images.

The RGB values of similar components in the two images are very much the same - the blueish clamp, the goldish bolts, etc etc. I'd suggest that these pairs of images are very comparable - and any differences are at least 75% real, and not artifacts of exposure or processing - of that I'm highly confident.

The 'events' Opportunity had were all overnight - so perhaps it is some nocturnal, or perhaps a dawn or dusk event, a time when the rovers are fast asleep - that causes whatever it is that made this happen. Maybe not dust devils per se - but a dawn breeze whipping over some rocks at a strange angle. Remember - Pathfinder took 17,000 odd images in less than 90 sols and caught a dust devil in three of them taken seconds apart.  Thus - given an average of 188 images/sol you should see one dust devil every 90 sols given Pathfinders conditions. Bearing in mind huge numbers of images at MEr are of the sun, dust opacity observations, MI, or of the ground itself - with an average of approx 92 images/sol for Spirit and 90 images per sol for Opportunity - many of which couldnt have ever seen dust devils - its little suprise that neither rover has seen one. 

If you dont see dust - you dont see dust - but it looks totally and utterly obvious to me that Spirit is much MUCH dustier than Opportunity - and, given the reduced power, and no other reason why such a power degredation might occur - it seems very very obvious.

Solar arrays with dust on would be lighter than those without. They're very nearly black when new - and martian dust is a butterscotch colour.  To compare the solar array colour in those images is folly - as that's what we're expecting to see a difference in. Compare other features, bolts, clamps, etc etc.  If things were covered in dust - they WOULD appear lighter

I'm sure you're not trying to be just awkward- but really - when I see dust as being so chronically obvious in those images - and yet you say it isnt - then what more can I say

You dont need a doctorate to tell you that you can tell NOTHING from a single greyscale raw JPG's that get put on the JPL website either.  You at least need to go to the trouble of making a colour image - and then - at least - compare it to Opportunity

If that doesnt demonstrate that Spirit IS dustier than Opportunity then what does.  It also demonstrates a possible cleaning action involving a dust devil or similar event crossing over Opportunity - picking up dust from the open flat array area, and dropping it at an area of low wind speed around where there would be turbulance because of the Pancam hold-down bracket.

The simplest answer is often the right one - and a perfectly simple and understandable answer is looking right at you in that picture.

You made the assumption that this patch of Spirit was 'essentially dust free' 

Oops?

Doug

Spirit is infact very VERY dusty - it's producing only about 400 whrs/sol - Opportunity, however, is almost dust-free and knocking on 950 whrs/sol

No one is quite sure why - but the recent rover deck surveys in L456 by both rovers, and MI images of the edge of the solar arrays are set to hopefully answer that question

Doug

If that were true - they'd have done it already

Doug

These rovers can not and will not confirm life on mars. They're geologist, not biologists.

What they CAN do is speculate that conditions may have been right for life to form billions of years ago

Doug

NONE of the images from saturn.jpl.nasa.gov work for me - i.e. no images on web-pages, none in the raw pages etc.

I'm using Firefox. Any pointers

Doug

Still nothing - almost a year after arriving at mars - published from the 2m res Super Res Camera

Doug