I think I can say with a fair degree of certainty that insects did *not* cause this pit.

-the other Doug

Are there any good images from orbit for the "true" etched terrain? I have had some difficulty finding this...

Thanks,

Steve

I'm absolutely agree with you, Doug! I prefer non-meteoric explaination, also because small crater should be rapidly canceled from wind/sand
erosion (think to Vostok)... anyway, should be explored deeply by Oppy!

An image of it with pancam would be nice...but they'll probably drive past it.

.........Anyone seen the classic 50's sci-fi moovie "Invaders from Mars" ? Where the Martians are hiding underground - the sand opens up and the victims fall through? That's what it reminded me of LOL.

The Martians arrive:


http://www.geocities.com/Hollywood/Hills/3411/images.htm

I already posted yesterday, but I don't find...
On sol 410, Opportunity already encountered other structures similar to this; here a mosaic of four Navcam subframes:

Based on this, I think meteoric origin should be excluded...

Why should be excluded?
It may be :-) A bigger impactor hit somewhere and lifted tiny pieces of rock in the air recently (a couple of years ago?), which made such small craterlets.
Look at the Oppy's trails, they still can be seen from orbit, and after exiting Endurance, there were very small differences in the trails left behind 6 months ago.So even in the windy Meridiani, dust deposition process is slow. And this "craterlet" seems with very round edges, so it is not impossible to have been formed years ago and not still been completly erased.

And sorry for my bad english, feel free to correct me anytime :-), I'd appreciate it :-).

I'd like to say (after some thinking), it MUST have been an impact. As far as i can see (but this must be confirmed with pancam or MI) there's an elevated rim around the feature. This can't be there due to a pit caused by a void underneath. There must have been energy acting from inside out / up.

Your explanation of a secundairy impact makes sense to me. Primairy impacts are either some meters at least, or the meteorite burns up completely and doesn't reach the surface. A primairy impact caused by a meteorite the size of a pea that has made it all the way through the atmosphere without burning up completely seems too rare to me to be witnessed by us now. Especially when you consider the wind action, that wipes out this small craters within decades, i would eat my shoe (dutch) if this is a primairy impact.....

If a primairy impact wasn't rare....the plains should be peppered by them (or are they filled up more easy compared to the bigger craters ?) Statistical analyses of crater density (also on the moon and mercury) show, that the smaller the impact, the more frequent they occur (that is, on an atmosphere free body). Then why are there more 5+ meter craters at Meridiani than smaller ones like these ? Maybe it's the wind action that fills them, or it is the fact that meterorites below a certain dimension simply don't make it trough the atmosphere....

Very interesting finding Oppy ! We should take a closer look !

Weird.........theyve moved back a bit

http://qt.exploratorium.edu/mars/opportuni...05P1214R0M1.JPG

My guess is, there *are* more small craters than 5+ meter ones. The only thing is, all "larger" craters within a certain area can be counted on satellite images. Dish-sized craters must be stumbled upon accidentally by Oppy before they are taken into account. So the sampling is skewed.

Resemble this hole not a bullet hole similar that would a bullet causes? Therefore I think it was rather a small meteorite that recently has fallen.

Have maybe anybody a picture of such a bullet hole in sand-like ground that he/she could post?

I understand what you mean. This certainly is an aspect that has to be taken into account. But the fact that it really is the first one in 5 km's of driving.....makes me think the smaller ones are the minority.

We need an updated rout map from Pando

http://www.geocities.com/vladimorka/MerView.zip
Simple image name decoder - you can browse your downloaded images or just paste any image name in the editbox and click 'decode' to have it decoded.

And I don't think oppy has moved much farther than Voyager - there aren't any significant nav images since sunday.

Talking about stumbling randomly I was looking at some old sol 95 images from Oppy and saw this dish shaped depression on the rim of endurance, Dish-sized crater or wind action?

I have gone to the trouble of making a stero pair which i have attached but can't figure out if it will pop correctly in the post.

Looks really fresh, though, doesn't it?

I think what we're seeing is the intersection of two surface-altering processes. The first is impact -- since Mars has a very thin atmosphere, the lower size limit of impactors that reach the surface is a lot smaller than here on Earth. But it's a lot larger than what would reach the lunar surface, for example. So, you get more craters from 6 cm on up than you do on Earth, but a lot less than you see on the Moon.

The second process is aeolian weathering. Over the course of just a few years, decades at most, this small little dimple crater will probably be covered over by sand and dust. Which means it's probably quite fresh -- a few years at most. Unlike on the Moon, where the most numerous craters are the zap pits made by grains of dust measured in microns, and where there are no other weathering processes happening, Mars doesn't retain craters of this size all that long. Because of aeolian weathering.

So, the impact flux of such particles must be pretty slow, or else we would see a bunch of these little dimples all over Meridiani in varying stages of obliteration. And we don't. In simple terms, aeolian erosion is happening a lot faster than tiny impacts are happening -- but both appear to be happening.

Seeing as this looks to be a very, very recent cratering event, let's bring up the topic of another thread, shall we? Perhaps this dimple was caused by a stray bolt, or fleck of metal, that separated from Oppy's cruise stage when it broke up and impacted at about a thousand KPH? I mean, going back to the Venn diagrams we did in grade school , there *is* an intersection of the sets "tiny craters made by very small impactors within the last few years" and "space debris that might have broken into some very small fragments that we *know* impacted close to here within the last few years."

I'm not saying this tiny dimple was caused by a tiny piece of Oppy's cruise stage -- but the timing and the size could well be correct. And it seems a bit coincidental that a really, really fresh crater should show up within what must be only several km of the debris footprint of Oppy's cruise stage...

-the other Doug