From Concepción to the "Twin Craters", and beyond... Options

[fredk]

I think we're still not seeing much of the far crater of the twins. Here's a crude estimate of where the two craters are (the far ellipse should be lower):

Amazing how we're basically on top of the twins and still can't see their full extent.

Mosaic is from Stu.

[nprev]

Not much in the way of ejecta aprons, it seems. Odd. Then again, Victoria didn't have much of one either.

[Bill Harris]

> Not much in the way of ejecta aprons, it seems.

This is the great puzzle here. One would assume that the Twins are older and that the ejecta rubble has simply weathered and eroded. But looking at the ejecta at Concepcion, expecially the NE ray, the weathered, still in-place material has a significant volume to be blown away without leaving a trace. By "without a trace", I mean no effect on the pre-existing ripples (except withing a few meters of the crater rims). I'd suspect that we may see a difference in the distribution of the blueberies since they would tend to be left behind after the evaporite matrix is weathered and eroded away.

There is more to this erosional process than what firrst meets the eye.

> Then again, Victoria didn't have much of one either

But it does. Eroded, very smooth, unrippled, it is clearly a blanket over the pre-impact terrain.

--Bill

[brellis]

hi all,

I tried to search for the answer to these questions, couldn't find 'em.

How many kilometers have the test rovers driven?

Have they tried to drive a test rover on a long trek like this?

Did they attempt anything like such a drive during the mission development stage?

Thanks, and as always, GO TEAM!!

[djellison]

Similar question has been asked before - but I think the answer was a 'don't know'

As for development? They were designed for 600 - 1000 m so testing them for 20km+ was never going to be a requirement.

[nprev]

I think maybe a more illuminating set of questions would involve the heritage of the drive system components & whatever testing they were subjected to if they've been used for any terrestrial applications.

Certainly Sojourner must have provided considerable pathfinder (ta dah, dah!) data for the MERs, but obviously all the moving parts are bigger, stronger & faster. Likewise, MSL's drive system is an evolute of MER; the questions are in what specific ways?

(OT for this thread, but very interesting. The engineering results from MER will probably be at least as valuable in their own way as the science over the long term.)

[AndyG]

The engineering results from MER will probably be at least as valuable in their own way as the science over the long term.)

That sounds dangerously close to suggesting you'd like a future MER sample/return mission!

Andy, still unable to reply with FF 3.6.2 ...

[Ant103]

Hi,

Back from a break (I think you can understood that sometimes we need to rest) of processing pictures, I started to make again (and again) colors of Oppy.

Much more interested by the pretty amazing view of Endurance rims on the horizon, like on Sol 2169 :

or Sol 2191


And here is the view of the approaching of "Twin Craters" (no names so I presume ?)

[Stu]

Good work, Ant, good work...

[Tesheiner]

According to the mobility info, we are there! Actually, 10m N of the west crater.
Can't wait for the images!

[Guest_Sunspot_*]

WOW that was quick, doesn't seem long ago they were 300m away.

[ngunn]

> Not much in the way of ejecta aprons, it seems.

This is the great puzzle here.

I seem to remember there's thought to be a certain thickness of Meridiani stuff (several metres, I can't remember how many) which erodes down until the covering of residual blueberries is dense enough to halt the process. Any crater too small for it's ejecta apron to exceed that critical thickness might be expected to erode down all the way to the original surface, leaving (as you suggested) an excess of blueberries as it's only trace. I wonder what that critical crater size is?

[fredk]

Hello twins!
http://qt.exploratorium.edu/mars/opportuni...DXP0717R0M1.JPG
The isthmus runs through the centre of this frame:
http://qt.exploratorium.edu/mars/opportuni...DXP0717R0M1.JPG

[fredk]

Isthmus in 3D:

Still hard to make out the east twin.

[Mirek]

My first panorama on UMSF:

Twin Craters


This post has been edited by Mirek: Mar 27 2010, 10:30 PM