Hi Tesh - it's been a long time since I have been able to visit here - and so glad to see that you're keeping up a good route-map! As usual.

I'll be looking forward to your latest update on where this new rover is. Thanks much!

I'm waaaay behind on the new interface, so hope my first post in years 'makes it'...

My thought is that Spirit should move toward a spot where a cleaning would be most likely. Can you recall instances of winds moving over Home Plate, and how many 'cleaning' events took place while there? (My memory is faulty, but I can vaguely remember only one.)

Maybe that isn't an option, but if closer to full power could be restored, I think the possibility of getting to 'the promised land' - or nearer to it - could be again looked at.

A P.S. - I'm going (Griffith Observatory) tomorrow at 4PM, events permitting... will post a brief report and a couple of pics, if I get any that might be interesting..

Doug (and all Los Angeles area rover-tracking folk) - this eve, Sat and Sun, there's an opportunity - here's a quote:

At Griffith Observatory in Los Angeles, the full-size rover model will be on display in the Depths of Space gallery Jan. 23 through Jan. 25, accompanied by rover team members from JPL. Talks about topics such as how the team drives the rovers and what the rovers have revealed about Mars will be presented in the observatory's Leonard Nimoy Event Horizon Theater. These talks, by JPL rover-team members Al Herrera, Scott Lever, Scott Maxwell, John Callas, Bruce Banerdt and Ashley Stroupe, are scheduled for the following times: 7 p.m. on Jan. 23; 1:30 p.m., 4 p.m. and 7 p.m. on Jan. 24; and 1:30 p.m. and 4 p.m. on Jan. 25.

For more information about visiting Griffith Observatory, see http://www.griffithobs.org/.

I'm sure hoping that 'attempt' is successful... if she could just get into some strong winds... there might be more life for her.

I agree - particularly about the magnet being a source - hey, that stuff is being held pretty firmly.

It is likely that a clod of dirt got kicked into the air by MER movement - pretty unusual, considering the very slow pace - but not impossible, given the right set of circumstances.

One scenario I can think of would be the weight of the rover snapping a piece of shale-like stone, causing an end of it to pop upward with enough force to toss a small bit of dirt into the air, part of which landed where we see it.

Considering the number of thin slabs we've seen (particularly around Home Plate,) and the uneven nature of the ground in spots, I'm surprised we haven't noticed even more evidence of small bits of dirt being tossed around by rover movement.

James, your great picture got me thinking again about the power needed to climb back out...

I'm absolutely confident that is not a problem, but I've been wondering about how much more power is needed to drive the rovers uphill versus that needed to go downhill.

Do you, or others, know if this has been covered elsewhere here?

Now... I've got to again express my Thanks to you, and so many others here, for all your efforts that provide so many great color renditions from the data coming back from the rovers. You all make this window into that other world the rovers explore a daily fascination not to be missed!

Thanks for the bar, Tesh - It's saved and soon framed!

Thanks Doug... for the adjudication - and for all the fun this place provides for so many!

Thanks, Kenny. If Oppy goes in today... I'll count myself extremely lucky

Wow... I did not know that, Stu - 'twould indeed be most fitting. Thanks for noting this little known (probably) fact.

That little dune may be more a danger than I first thought - or is it not as high as it looks?!

Well, I'm out of it now... I got close - centsworth II now looks to be the closest guesser at this point... maybe.

Fox News is carrying an AP story on the "very old rovers' HERE.

The story sez, "During the storm, each of the rovers spent a couple of weeks sleeping most of the time."

Didn't they spend a lot more than a couple of weeks sleeping most of the time?

One quick thought before racing out the door (late to work)... perhaps the right camera benefited a bit from the position of the arm.

There is an interesting article about dust storms on the hubble-site HERE - that foretells a possible second following storm. (Hope not!)

Here's the relevant excerpt:

After three months, the storm is beginning to wane. The planet's shrouded surface has cooled, and this allowed the winds to die down and the fine dust to begin settling. However, Mars is approaching the closest point of its orbit to the Sun. Once the atmosphere begins to clear, the return of unfiltered solar radiation may trigger additional high winds and kick up the dust all over again. This one-two punch has been seen in previous Mars storms for centuries.

The article is old - but could multiple storms be caused, or have been caused in this fashion with this episode?

It's nice to see new folks joining in the fun here - particularly someone that has come often but never posted.

Your experience has been mine as well... many have asked me what state various Mars photos were taken in, and I've much enjoyed the various reactions when I tell them the photo is a composite of many that were recently taken on Mars - and point them to this website. I know several that are still 'lurkers.'

a post script...

I've lived for many years in the American Southwest - in the desert areas of Texas, New Mexico and Arizona - where many times I have seen whirlwinds operative well after sunset, one specifically that I remember well, that nearly took me off of a telephone pole near Lordsburg, NM at just about midnight.

At other times, I've seen multiple twisters in the moonlight northwest of El Paso, TX and southwest of Globe, AZ.

None of this means DD's happen at night on Mars, but I've seen nothing that proves that they don't either.

"...it was unlikely to be DD's as one of the cleaning events was at night." - Doug

Well, while it is true that most whirlwinds form during warmer sun-lit afternoons, it is not true that this is the only time they form. We know that wind still blows at night (as implied) - and we know that craters of the right size, depth and formation create many whirlwinds that travel great distances before they collapse.

So statements that a whirlwind cleaning would be unlikely simply because an event took place at night - or statements saying that no whirlwind ever caused a cleaning event are both rather shortsighted and proof-less in my view.

One last point - I don't know if there is likely to be wind at Victoria at this time of year, but if there is any likelihood of wind - Oppy should stand by where she is for a day or two in the hope of getting several nice cleanup jobs done on her solar panels.

It would have been most interesting had the operators taken photos of the panels before heading into this likely place to get a cleanup job done - and some after photos afterward, if there is any wind...

I'm late to this dust-up... mostly because I didn't think there was much doubt about what causes the dark wind tracks at Victoria. However, obviously there's a lot of people thinking 'deposition' versus 'swept.'

When you look at the same light-dark phenomenon at other craters, it is easy to see that it is wind-caused - almost always in the prevailing wind direction, and often extended by vortices ('dust-devils') ranging from small eddies to well-formed powerful whirlwinds that form in craters and travel some distance before collapse.

Whirlwind formation happens best at craters of the right size and depth for a given wind speed and time of year. Below are two pictures showing whirlwind tracks that begin at craters and travel various distances away - note that all of these craters are not known to have dark material inside them to provide 'deposition.'



Vortices cause the 'deposition' folks a problem because they don't pick up dust in a column until they are well formed which occurs after exiting the lee side of a crater, then they carry it away dropping it across a large area down-wind after the column disintegrates.

At larger or smaller craters whirlwinds of any strength are rarely well formed and their 'tracks' are shorter - as at Victoria, and the famous 'double crater' below.



At Victoria as at any crater, there are times of the year, and times of the day, that these tracks appear darker due primarily to dust removal, and the effects of lighting and reflection of light. Below is a picture of very dark wind-tracks at Victoria - and a picture of Oppy's tracks taken shortly after leaving ‘Jason' on Sol 382 that appear light.

Bottom line, when these wind tracks at Victoria are the darkest, they are more likely caused by dust removal than highly unlikely greater deposition of dark material from within the crater - and Oppy's tracks can appear light or dark depending on were the sun is more often than what the material under the wheels is.




I don't believe the presence or absence of 'blue-berries' has any effect or plays any part in the appearance of the wind (most likely numerous small whirlwind) tracks at Victoria.

YIKES! The rover is close to the edge... They took more risk than I expected, and the rover said, 'Hey, no big deal - I can do it!

That's quite a neat pan, Tesh! Thanks much...

Too bad this wasn’t noticed and looked at more closely before it was left so far behind, since now speculation will run ahead of probability.

The cracks that run three quarters of the way across the dark spot, and down-picture at 90 degrees from that crack suggest some upward force. (But I doubt it was much - or maybe any.)

It could be a section of stone just under the surface, that was moved by the weight and passage of the rover wheel - possibly raising it just enough to cause apparent cracks - by passing over perhaps an edge or end of it.

If a piece of rock were moved slightly, it could disturb surface material and expose some darker material underneath - perhaps contributing to the effect of a ‘circle.’ (Though one would expect to see more surface cracking - - and the ‘cracks’ may not be cracks at all.)

Note that material below the ‘circle’ and spots to the upper left of it are also of the same or near the same color.

Note too, different colored spots frequently occur naturally here on earth that are sometimes near-perfect circles. They are most often caused by wind, and a stone or other object just underneath the surface. My best guess - this is a photo of the same type of action on Mars.

Well, I think there is ~some~ desire to enter the crater sooner, rather than later... but, from past experience, patience has been the ~usual~ approach. They will, I think, look longer and harder at the possibilities - and try to chose a path that at least offers the possibility of exit after entry - the best opportunity (no pun intended) to snuggle up to lowest-level exposed layers - and the best sunlight (seasonal) exposure for the attempt.

I'd guess they will circumnavigate (because they will probably need a later-in-time seasonal entry time) - and they may attempt to catch some of the cleansing winds where we see the whirlwind tracks at bays C5, D2, and D5 (with probability emphasis on D2) - which could mean a somewhat extended or slowed approach at that point (depending on the seasonal likelihood of wind at the time - and the best balance with sun position for entry.)

So - to toss out a number, I’d expect an entry decision to come no sooner than about sol 1190 - unless they stumble onto what looks to be the perfect spot sooner - maybe somewhere on the other side. But, I don’t believe that's likely.

It is likely that at current operational speed, they could take as long as 220 to 250 sols to circumnavigate the crater - or as few as 110 to 150 days - if for seasonal reasons (sun) they must hurry the trip, and because Duck Bay or other spots looked better.

Because it is of advantage to look closely at all the possibilities, and considering the advantages of a few cleaning ‘events’ - I’d tend to think an entry date further along rather than sooner may be likely - somewhere near sol 1285.

But, if the sun is best in the late spring, early summer, I’d bet against the ‘full-tour’ - and look for an early and speedy return to Duck Bay for entry - backtracking after a possible relatively-short attempt to find ‘cleaning events’ - and entry when 'acceptable' power is available, at Duck Bay.

Anything can happen to change - everything - but an August date here on earth for entry would not surprise me in the least.

As with Spirit's local where winds develop in the summer, I'd expect similar seasonal effects at Victoria too.

Since the wind 'tracks' are relatively short (and wider) by comparison to many seen at craters in Gusev, it appears that the size and strength of the whirlwinds that form in Vicky's bowl are probably shorter-termed, somewhat weaker, and less tightly concentrated than those observed at Gusev.

Tx much! I got lost, thinking the rover went further than Verde - around the crater, but this was a run to the end of Verde itself! (Much longer run, looking at it in the photos than I expected!)