Then and Now, Changes over time Options

[MizarKey]

Of course we've seen similar side by side images showing the changes between the years. I never get tired of them...

Here's a couple...from 06/05/2000 M1600291 12.02m/pixel and 08/16/2005 S0901626 3.21m/pixel

I rotated M1600291 so it would line up with S0901626. I didn't really scale them efficiently, M1600291 appears at 2x while S0901626 appears at 0.5x

You can see that a couple of the 'seeps' (dust slides or whatever) are new. The other section I enlarge 2x from S0901626 I thought interesting as the 'dust' passed over two outcroppings but only made them slightly darker while the rest of the trail is quite a bit darker...I would think the darkness would be more uniform...maybe the dust didn't stick to the outcrop so much?

Attached thumbnail(s)

 

[MizarKey]

There is nearly a 4:1 resolution difference between the older (right) and newer image. However, on the newer image there is a 'new' black streak about midway down the image on the left side. Not much of a change in 5 years, but at least something is happening on Mars and it's not just a static place.

[Guest_Richard Trigaux_*]

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Yes I found it, a thin one but very dark (more fresh than the others). It is a bit confusing, we could confuse with other smaller tracks, but this one seems new, and we can rely on the shape of the nearby rocks to compare and eliminate confusion with the other smaller tracks. I am not certain, but you are anyway right that we must stay alert. That only some things like that are found, and it would give us a clue on how common they are in time.

What we don't know is how fast such avalanches flow? is it a creeping process, which could take thousands years, or a catastrophing process lasting some seconds? The only thing sure is that this time is much shorter than the time needed to whiten the traces (otherwise we should see tracks with the top white and the bottom dark). And I guess it is not fast enough to have inertia effects on the avalanches.

We don't know too how many time is needed to whiten the tracks. After what we saw on Spirit and Oppy's solar cells, dust can be deposited very fast, and a change in colour could come in only some years. Then the time between two avalanches in the same place would be in the thousands years, at rough guess. And tens of such avalanches could take place every year on Mars. The odd for an amateur to spot one is still low, as only few images are available on the net for comparizon. Perhaps a software could work on images to find such changes.