Just how significant was this cleaning event? 800Whr was mentioned, what is this up from, 600's range?

Still, 800 is amazing after almost 1200 sols

I think it's been multiple modest events - 800 is astonishing really.

Doug

It's very impressive but not all that surprising given the rapid approach of mid summer and with the benefit of hindsight. On average the deposition\erosion rates are proving to be pretty closely matched over the scale of years. On shorter timescales you get temporary dust buildups and a temporary removals depending on the season and some other factors (local storms, global storms, orientation) but the general regional averages are close to zero net deposition or erosion on the annual scale. If it was anything else there would be mountains of dust around the rovers. Luck has played a significant part - at almost any stage in the missions a global dust storm would probably have ended things for good within a few days.

Still, no-one would have said that heading in for 2 martian years on the surface we would see Opportunity generating close to 90% of the power it was planned to have at the start of the mission. Sweet.

Opportunity moved a bit on sol 1175, just enough to have "Cercedilla" into the IDD workvolume.

http://nasa.exploratorium.edu/mars/opportu...23P1151L0M1.JPG

Here is jvandriel's panorama in polar format...

Phil

Click to view attachment

Sweet indeed. Hopefully not OT here, but this makes me wonder if we shouldn't build a few more MERs (with augmented payloads at least, of course) and really hit favorable areas like Meridiani for intensive, very specific geological investigations.

A few years back before they were launched, I mentioned to someone that the MER's lifetime would probably be chiefly constrained by dust buildup on the solar arrays. He asked why they weren't thinking of carrying some compressed air canisters to blow off the panels.

It seems that Nature provided this after all, and cleaning events are most effective and negate this constraint, provided that the vehicle is located in a region amenible to such events. Do we have enough data yet to factor cleaning events in for mission planning? If so, might be a really good Discovery proposal or two here for somebody...

Cleaning events are great, yes -- but you have to be able to get into the proper place for them. Obviously, Spirit is not well located for such an event at present, and is getting dustier and dustier.

We could lose Spirit to even a small, localized dust event at this point, she's so dirty. And it'll be a little difficult to drive Spirit anywhere that sees regular "high" winds, I'm afraid.

That said, I'm always very glad to see cleaning events for either rover. As long as Oppy remains here at Victoria, I think we have some real opportunities to drive her over to a windy spot along the rim and clean her off when she gets REALLY dusty...

-the other Doug

Imaging plans for sols 1177 and 1178 continue to name the nearby features like places at Madrid's (Spain) northern mountains.
I'm really enjoying that because I have been on all these places many times.

Sol 1177: "Carpetanos" (Hills), "Somosierra" (passage), "Matabueyes" (Hill), "Morcuera" (passage), "Pedriza" (rock climbing area).
Sol 1178: "Claveles" (Peak & Lake), "Pajaros" (Lake), "Valdemartin" (Hill)

Realistically, I think Spirit is unlikely to see more than Michaeltree Ridge/Home Plate in the remainder of its roving career, no matter what the situation with dust on her solar panels. At some point in the future, I suspect we'll see death from dust deposition as a mercy killing for the rover.

Spirit's a working scientific platform on Mars so you can't really use the term "mercy" killing. It costs big bucks to get there but now each day of life for Spirit is a bonus and ridiculously cheap compared to cost of putting her there in the first place. And valuable stuff comes back every day.

So the longer they keep her sending back data the better. Hopefully they are thinking of ways to get the deck into the wind somehow to get another power windfall.

Spirit is ready to get some clearings as the season approaches, dust devils are forming more often now as observed in that thread.. i expect spirit to get another lease on life in the next few months (yeah, off-topic, sorry!).. i guess its time to create a "Pool for Spirit cleaning event yielding power above 700Whr" thread


yeah, Oppy is looking pretty clean compared to very dusty Spirit

Agreed. Look at the Voyager probes. Very few instruments still work, and power levels continue to decline, but scientists still get data from them on a regular basis.

Even if Spirit's power level drops to the point where it can't move, it can still be useful. NASA wants to send Phoenix to Mars, which is stationary to begin with. We'd just have a really dusty, wheeled, stationary lander named Spirit. When Spirit fails to wake up one morning, I think that is when they'll finally think about calling it quits.

Bah, these two rovers will last forever. MSL will be a slightly radioactive lump of metal before these two ladies stop working. Anyone want to start that pool?

Sorry - which forum is this again?
Unmanned Spaceflight.com > Mars & Missions > MER > Opportunity > The drive back to Duck Bay

Not going to start moving posts - but discussins about Spirit should happen in the Spirit section.

Doug

Sorry Doug, they're talking about Opportunity in the Spirit section. </ducking>

(kidding!!!!!)

Mmm, this thread needs a "bump" so let's do it.

Here is a polar projection from the current site where Opportunity is parked investigating "Cercedilla", a little town at the "Sierra de Guadarrama" (oh, that's a rock too ). I took the time to locate on the image all the features imaged up to date (sol 1179), all of them part of the "Sierra de Guadarrama" theme.

Click to view attachment

Thanks, Tesheiner! I can't wait for those Guadarrama closeups!

Responding to Rocker's question (moved to this new thread, by the way), I had thought these sol 1177 pancams were drive direction, and I was wondering if that meant they were done here. I had been hoping they would spend more time here, and even approach closer to the top of Lump to study Guadarrama up close.

But that was four sols ago now. Can anyone who monitors the pancam database glean any clues about their plans?

Really, this stop at Lump was a great bonus, as it wasn't mentioned in the official "plan". Hopefully we'll get a better look at other targets, such as Guam/Dock and the Beacon area on our way back to Duck.

> I had thought these sol 1177 pancams were drive direction

Yup. It's not the first time they take those "drive direction" shots some days before leaving a site. In other words, the driving plans may be already defined and planned since sol 1178.

NOW, I've just checked "the codes" in the pancam database and found this sequence below planned for sol 1182:

01182::p2426::10::4::0::0::4::2::10::pancam_more_drive_dir_L7R1

My take is that they were not convinced by the previous dd images. Let's see what is downlinked.

We appear to be still getting strong wind gusts. Here's an animated gif showing the front hazcam view for sols 1175, 78, and 82. The biggest changes are near the right front wheel:
Click to view attachment

OK I'll ask the obvious question:

Do you think those streaks are erosional or depositional?

(Just kidding. I really don't want to initiate another long debate).

Great catch, fredk.

Gray: I don't want to go there, yet, but this does look like deposition in the lee of the right wheel. One of these days, when it gets slow, I just might revive the great dust debate. I am still not convinced by the brief explanation that was provided.

Sol 1184 is just beginning for Opportunity, and it seems to be a packing & driving day: take a few shots of one more feature --called "(La) Peñota"-- at this site and probably leave the Cape of Good Hope.

Meanwhile, here is a 360º navcam panorama taken at the current location, combining images taken on sols 1175, 1176, and 1183.

Driving day it was. Looks like a good long drive. Farewell Lump!

Does anyone know what is on the horizon here?

Here's a polar view of Tesheiner's pan. I think Opportunity drove to the top of this view. then turned left and is near the 11-o'clock position now (sol 1184).

Phil

Click to view attachment

Beagle Crater?

The azimuth and profile seem about right. I can't imagine what else it could be.

Some interesting scenery...

Click to view attachment

... and an old friend with a new feature...

Click to view attachment

Nice images Stu (as always).

The circular brush marks on the lower image give it a dinosaurian eye.

http://library.thinkquest.org/C0128701/Pic...lociraptor3.jpg

Your eye saw what mine saw, Gray! Here's an animation (from Stu's images) of the Great Martian Beast Cercedilla, winking at us all as it munches on its hearty diet of blueberries (high in iron, apparently):
Click to view attachment

Very nice!

Strange that just one berry (in the circle) should move so much. I remember in the
last moving berry movie, it seemed the movement might be due to sand supporting
the berries blowing away and allowing the berries to slip or roll down a slope. But I
have a hard time imagining that in this case. And so much movement from one berry
in the entire field?
Click to view attachment

Wow, LOVE that animation! Would never have spotted that moving berry without it, thanks!

Have made the colour of #2 closer to #1, if that would help someone make a smoother animation...?

Click to view attachment

Just noticed... couple of changes at the top there....

Click to view attachment

Here is the Mi mosaic taken on Sol 1176 and Sol 1178

before ratting.

jvandriel

and here is the Mi mosaic taken on Sol 1182

after ratting.

jvandriel

Yeah, that's really interesting, I hadn't noticed the moving berry. Is this the first purely wind-moved berry we've seen? There are lots of subtle changes in the soil colour between berries. Here's an updated animation using Stu's new image, with some adjusting of my own, and covering more ground:
Click to view attachment

I've posted some views from sols 1175-1184 here

Yeah, I noticed that, too. The appearance of the darkened area at the point of the rock is almost as if water was squeezed out of the rock and flowed out from the tip and onto the ground. Of course, that's not what happened, but it has that appearance. Instead, I next thought that perhaps the RATting of the rock pushed the left edge into the ground and levered the right edge and tip a bit off the ground, resulting in soil disturbances, but I see no other signs of soil disturbance anywhere else along the soil/rock interface.

My best guess about that dark patch is that the vibration of the RATting caused the soil to shift a bit, but if that's the case, I would have expected to see other patches of disturbed soil along the soil/rock interface.

I think that the berry movement is *probably* wind-related, but I suppose there is a very minute possibility that it was caused by RAT vibrations. However, if the latter were true, I would have expected to see more berries moving.

One intriguing possibility is that the single berry that had been sitting on top of the rock, at the RAT site, was energetically ejected from the RAT, flew through the air, impacted the berry that shows significant movement, rolling it down several centimeters. This explains the unusually large movement of that single berry, when none of the other berries have moved significantly -- you'd think that if wind *or* vibration caused that single berry to move, that others would have moved just as much. Hard to imagine a gust of wind that's powerful enough to move that one berry, but not powerful enough to move other, smaller berries elsewhere in the scene.

-the other Doug

Hello,

As said in THIS post, I'm very late to posting pictures.

So, here is Grenada on the Sol 1160 :


In the same time, tanks to all who made pictures

...no kidding! All I can think of is that it's perhaps unusually spherical, and that the rest of the berries are embedded in matrix or otherwise constrained...does this tell us something about local soil properties (i.e., surface evaporites)?

On the other hand, maybe it's just mating season...berries need love, too!

This is our best look at Beagle Crater in a long time, from sol 1194:
Click to view attachment

... and this is our best look at the beacon in a long time too, from tosol (1198).

http://nasa.exploratorium.edu/mars/opportu...PKP2431R2M1.JPG

If we had a microphone at Victoria - I think you would hear a V8 rumble.

Doug

You thinkin' James Dean in "Rebel without a Cause" or the last scene in "Thelma and Louise"?

At this pace we might be again at the tip of Cabo Verde by the end of next week.
Four/five driving sols.

I'm not in any kind of hurry or anything, but do you think Oppy could be back at Duck Bay before Sol 1219?

"
blink.gif ...no kidding! All I can think of is that it's perhaps unusually spherical, and that the rest of the berries are embedded in matrix or otherwise constrained...does this tell us something about local soil properties (i.e., surface evaporites)?

On the other hand, maybe it's just mating season...berries need love, too! "


The berries must be floating in puddles of water

Good try! You're VERY close to have put your quote in the right thread

Should be back soon, but do they have approval yet to enter?

Brian