First pictures of Mars Rover (Opportunity) "trenching" . . . comments/speculation encouraged

NASA - JPL ^ | 2-16-2004 | NASA/JPL

[Phil V.]

Comments/speculation?

stereo strip of trench . . .

[#1CTYankee]

Hole shot!

[sine_nomine]

Did they file an environmental impact statement before messing around? I think not.

[rhombus]

After a white powder was discovered, Mars was shut down while Hazmat teams combed the planet. Government workers were sent home early.

[Frank_Discussion]

I'm fighting a VERY strong urge to say the same thing... ooooh man!

[Frank_Discussion]

It cost an awful lot of our money so you can write your pessimistic bullsh*t.

[Don Joe]

Each of the rover wheels are attached to their "drive train" on the tread side, inside the wheel. Thus, their fasteners leave marks in the sand as the rover wheel turns.

I looked at that site (http://www.2020hindsight.org/2002/09/22.html), and it says that "This rover wheel is constructed from a single slug of aluminum."

That being the case, and looking at the photo (which bears out the "single-billet theory" :), it looks like the "hash marks" visible at the bottom part of the tread are milled into the surface to give a visual distance indicator in the tracks it leaves in the dirt. (i.e., they can see the marks in the tracks, and calculate actual distance, since the wheel's diameter is known.)

[Frank_Discussion]

It's the dang Tolan again!

[Shryke]

RE: post 156 pics.

That clearly looks like the top of an Entenneman's Coffee cake, partialy obscured by Nestle's Quick.

Did I mention Atkin's diet has some curious long-term side-affects?

[Don Joe]

Now that I see that close-up picture of the "hashed" part of the tread, I suspect they milled it into the wheel for two reasons. You can see that it's more than a visual indicator -- it's beefed up with a variety of deep triangular ridges, and, there's a rectangular hole going right through it. I suspect that when the rover was stowed in its carrier, it was with that section down, and each wheel was locked to the carrier via a post going through the hole.

[Colorado Doug]

Why does the picture of Mars from the rover look round?

Mars is much smaller than we thought it was.

[My back yard]

Yeah, I thought reflected light also.

[Don Joe]

Here's a web site from the guys who made the rover wheels .

Yup, I was right -- it is a "mounting pad". (I guess I should read ahead a few posts before posting replies, eh? Argh...)

[Don Joe]

It appears so bright (like talc, or magnesium silicate) because of the abrasive effect of the wheel. And it's soft enough (again, like talc) that, as the wheel climbed out of the trench, it left a trail of powder from the rock.

Or, if it's really hard (and rough, abrasive surface) stone, the white powder could be aluminum scraped off the wheel's ridges.

[The Radical Capitalist]

As I recall, the topsoil changes color when under pressure. The first pix at this site showed impressions in the dirt where the cushioning balloons of the lander hit. All these impressions were much brighter than the surrounding soil.

[Don Joe]

So the suggestions that the white substance might be ice or perma-frost or that Mars may be at its core an ice planet similar to Europa . . . also unproven?

I would doubt that, given all the volcanoes.

[Don Joe]

I suspect that once we establish good seismic stations we will find that Mars has a small core, similar to the Earth's...with very little, if any, seismic activity.

I'm not a geologist, but my WAG theory of why we have tectonic plates moving around on a soft mantle is because we have oceans, and a moon. The moon keeps the stresses moving, which creates heat, and helps "break up" the surface, and the oceans (due to the moon) provide a massive amount of weight constantly shifting back and forth on a daily basis. Mars, having neither a large moon, or oceans, would therefore have very little sub-surface activity other than the static volcanoes. ("Static" in the sense of standing still over the same underground "stuff", not in the "plasma sparks" sense our no-longer-with-us poster waxed obsessive over.)

[Don Joe]

About 40,000 tons of ~0.2 mm micrometeorites fall to Earth every year.

That's interesting. Do you know if there are any stats on what percentage of earth's topsoil is comprised of this stuff?

Aside: my ex had a rock, probably about 12-15 lbs or so -- that her grandfather owned (along with many others -- he was an obsessive rock-picker-upper from wherever he'd travel). She said that one of his rocks was a meterorite, but she didn't know which. I decided that this one rock in particular had to be one, based on the strange melt/streak patterns, and the way it felt so solid. We had a prof from the local university's astronomy dep't look at it and he was drooling all over it, saying yup, it was a meteorite, and wouldn't we love to donate it to the school? No, we wouldn't.

It was among the few items she took after she and someone of unknown identity busted into my house and lifted -- after trashing my entire house, letting the dogs run free, with the door wide open -- when my father told her I was visiting friends in NYC. That was when I decided it was best to be very secretive about where I was. Argh.

end_grumble

[Don Joe]

(Not to go "Close Encounters" about those clumps but they DO look SO familiar...remind me of...something...Something from long ago when I was a kid and dug in the dirt...something >kinda< important. LOL)

They remind me of two things: salmon eggs, and those humidity-retainer balls that people mix in with soil they're planting things in, to hold, and slowly release water for the roots.

Not to digress (too much), but I'm surprised there's been so little discussion of the two rocks that look very much like eroded conch shells. One would be interesting enough, but two of them, in close proximity to each other, hmmm... it makes me go hmm...

[Don Joe]

Perhaps not, but it is fa-a-ascinating to speculate.

45% oxygen?

[Professional Engineer]