Agreed. There are plenty of ~8-12 pixel diameter bright spots that could conceivable be part of MPL, but don't have any features that allow a definitive conclusion.

I'm still somewhat optimistic about finding it. As previously mentioned, a good part of the predicted MPL ellipse has not been imaged by HiRISE. It may be sitting there plain as day. The evolution of the Phoenix site over the next season may give us a hint as to how realistic this is. If the parachute is undetectable after the first spring, that will bode poorly for finding MPL.

How much of the landing ellipse did MGS cover?, I think the parachute ought to be fairly obvious even with MGS. With Phoenix landing so far down range of it's target - almost outside its landing ellipse infact, perhaps the same happened to MPL, and as others have suggested, we still don't have images of the area it lies in.

I wonder, if the failure scenario reached by the review team is correct, could MPL have survived the landing in some functional condition? Would the solar panels have been deployed? If not the lander will appear even smaller than illustrations indicate.

I know there was some excitement a few weeks after landing when reviews of communications attempts with MPL suggested they may have received some very weak signals, enough evidence at the time for them to re start communications attempts.

Another backshell rock sculpture from 005536_1030? Or an actual piece of MPL?

Click to view attachment
(zoom is 100%)

This sure looks bright and shiny, but I think it might be too large to be the backshell. Also, the way it's conveniently nestled into an indentation in the side of the fracture suggests a natural origin.

What is the exact size of the MPL backshell?

--Chris

The MPF, MER, MPL and Phoenix backshells are about 2.6 metres diameter. The Viking backshells are about 3.5m diameter

Thanks. Looks like that rock is nearly 2x larger than the MPL backshell then.

--Chris

Regardless, that is a cool feature

There is a roughly circular bright object at pixel 36359,42905 of image ESP_013289_1035_RED.jp2. Within this object, on the right side, is a smaller white circle that might be the backshell and which measures 8 or 9 pixels (~ 2-2.25 m) in diameter. It is most brightly lit roughly in its center. Bunched up against this putative backshell, mostly on its left side, would then be the lumpy collapsed parachute. Stretching to the upper right for about 10 meters is a faint stringy-looking feature that would then be the parachute cords laid out and then doubled back. Judging from the HiRise image which includes Phoenix’s parachute cords, so the length here is about right.

This information was presented to the HiRise principal investigator who dismissed it, but he made several errors in his short reply. He apparently looked at the whole object, measured it at 4.5 meters and then stated that nothing on MPL was that large. In fact, the inflated parachute could measure as much as 8.4 meters across, so 4.5 m would seem plausible for a collapsed parachute plus backshell. His second argument was that the candidate was not sufficiently different from the terrain. This is a subjective call, but at the 1:1 scale, or a few steps up or down, there is nothing in the terrain resembling it in the field of view. It does catch the eye. Mine, at least.

Finally, as near as I can make out its lat/lon, it is at 76.55 S, 165.45 E. This is very near the center of the 2 sigma ellipse for the reconstructed trajectory.

I don’t know that it is a part of the MPL hardware, but that after scouring through several HiRise images of the area, this was the only plausible candidate I saw.

P. Fieseler

Very interesting and great search.
But looking at it closely, it seems that this "white circle" casts NO shadows, unlike other features nearby (and unlike other backshells saw on MOC images).
Also, the "parachute" is not really different from lighter ground nearby...
Bon courage for your search !

Of course if you dropped something from 100 meters it would tend to acquire a flattened shape and therefore cast no shadows

I will say that this is the most interesting of any of the candidate objects I've seen. My sense is that it's too big?

Thanks for taking the time to respond. It is admittedly an ambiguous object, but I wonder if people are seeing the shapes the way that I am. I will attempt to repost the image with a cartoon of what I see (or imagine that I see). The details, especially the parachute cords, are clearer in the viewer than these posted jpegs.

A parachute flat on the ground would not cast a shadow. An intact back-shell should, however. Perhaps the soil there is soft or mobile.

Vesta, I think your "parachute cords" are actually a small bluff, and are the lower right edge of a small hill on which your interestingly VERY round small thing on top of a bigger round thing lies.

Definitely worth another look, preferably with a different illumination angle.

Not crushed as flat as this, being slowed down at least a little by a parachute. All other backshells came down fairly intact as seen on images taken for other missions by MRO (Viking, Pathfinder, MER) and the lander themselves (MER) (

Always beware the mind's incredible ability to see patterns where none exists.

High-Speed Turtle

Especially on Mars!

--Greg :-)

I was sort of joking, imagining a coyote-roadrunner cartoon. But the present theory is that the descent thrusters cut off when the landing legs deployed around 100 feet prior to touchdown, so the parachute was long gone. One could imagine however a soft soil where the craft did a combination of collapsing and embedding such that you have a debris pile that casts little or no shadow.

A thought just occurred to me: If the thrusters did cut off prematurely as in one of the leading theories, would MPL still have been aerodynamically stable during the fall?

I don't know if the atmosphere would have had any significant effect during that short distance (even if it was windy), nor do I know where the vehicle's center of gravity was located. Did MPL have static stability, or were the thrusters totally necessary to keep it normal to Mars' gravity at this stage of the descent?

This could definitely have some bearing on how the wreckage might appear from MRO.

I think a lot will also depend on how Phoenix looks to MRO after the ice has disappeared. The wreckage of MPL has been embedded in ice at least once before most of the available images were made, so how much effect does this have on for instance the parachute, will this still be visible after one winter or will it be completely covered by dust and dirt?

The terrain at the MPL site is just terrible, you can easily hide hundreds of landers over there. Quite apart from that, there is so much uncertainty about the final fate that we can't be sure what we are searching for, if the engines indeed did cut off 100 feet of so above the ground then I would guess we will be looking at a mostly intact craft, more or less similar to Phoenix, but if it failed very early in the EDL then you might never recognize it. One point is, if it failed very late, why didn't we ever hear anything from the two penetrator-probes which were released very early?

From what I heard those probes were so badly designed and not tested to the standards we might expect, that had MPL succeeded we probably never would have heard from them anyway. But I'm just reporting anecdotal recollections. I'll have to look up the specifics.

The most likely failure as the investigation concluded, would be an early shut down of thrusters. This means, on the surface, there should be a heatshield, like Phoenix, a Backshell and Parachute, like Phoenix, and a crashed lander.

I'm still looking at the PHX landing sites HiRISE images of the new season, trying to find the landing site - and can't.

Whilst casually poking around to see if I could turn up a copy of that report, I came across this story reporting Michael Malin "possibly" identifying the MPL wreckage. Has this site been reimaged by HiRISE? I haven't found subsequent news on this site, probably my google-fu is weak...

Yes it has been seen by HiRISE, but even before that it was re-imaged by MGS. Malin withdrew his interpretation of that feature, and now we don't know where it is. The HiRISE image is on here somewhere if you look back.

Phil

If you want to expand your search beyond the MPL landing ellipse, you might try looking at CTX images as well, as the Phoenix hardware is all visible in CTX.

Has the entire landing ellipse been covered by HiRISE now? If the hardware were as obvious on the surface as those of phoenix/MER etc, I would have thought something would have been seen by now. Im wondering if we will ever find it now. Or perhaps something else went wrong in the early decent and it was destroyed in the atmosphere.

The last comment I saw from Tim Parker was that a small spot in a CTX image outside the HiRISE coverage would be looked at in HiRISE as the season became favorable again.

Phil

Yes, it has, and CTX acquired continuous coverage of a good area outside of the ellipse as well. As one of the CTX science operations team members, I can tell you that we've looked at all of the CTX and MOC images in and around the ellipse and haven't found anything particularly promising. I'll be interested to see what the spot is that Tim Parker is referring to.

Tanya, let me be the first to welcome you to unmannedspaceflight.com! I'm sure I can speak for all the members when I say I'm looking forward to your perspective on stuff in space! CTX doesn't get nearly enough love -- just by posting here you'll help to get it a little more attention.

[But ewww, a Wesleyan grad. Go Ephs.]

I think that may depend on your definition of "entire landing ellipse"; there were several based on various assumptions of atmospheric conditions and entry state, some larger than others. See http://www.msss.com/mars_images/moc/1_24_0...nder/index.html though I am not sure what current thinking about this is.

Thanks! CTX is definitely under-appreciated by both the public and the scientific community. It is an AMAZING dataset, and the images are simply stunning. Part of my job is to look at every image that comes back from CTX each day, and I never get tired of it.

Here is a CTX image (P22_009725_2484_XI_68N125W) of Phoenix from back in August 2008; admittedly, this doesn't showcase the CTX at its best as the image is a bit murky, but that's hard to avoid at the Phoenix landing site:

That's cool, it certainly stands out! -- and an advantage of lower resolution is that the image doesn't look as cruddy as the HiRISE images from the same time period

To get to the full CTX frame knowing any image number, append "http://viewer.mars.asu.edu/planetview/inst/ctx/" to the front, so this one is

http://viewer.mars.asu.edu/planetview/inst...2484_XI_68N125W

I was just reading this article on the difficulties of finding/identifying non-human artifacts around the solar system (http://news.discovery.com/space/our-solar-system-might-be-littered-with-alien-artifacts-111109.html), which included this picture of the 14 ft wide Lunar Surveyor 6 lander, as seen by the LRO:

http://blogs.discovery.com/.a/6a00d8341bf6...15b68970d-800wi

The low sun angle really makes this lander stand-out clearly as a spike of shadow. Certainly it could be confused with a boulder, but at least in this case there're not a lot of boulders around to confuse the issue. This leads me to wonder whether the search for the Mars Polar Lander might be revisited using low sun angle images from MRO. Or was this an aspect of the existing search?

Given the latitude of the MPL landing site - the sun is always at a low angle.

I estimate that it could range from about 0 to 50 degrees depending on season and time of day. I would consider low sun angle to be less than approximately 15 degrees to yield a real benefit in feature recognition. If the terrain is as flat as what Phoenix observed, MPL should leave a very prominent spike of shadow at such a low sun angle. Obviously this would be less-so in rocky or high-relief terrain. Scattering from dust in the atmosphere would weaken the contrast of the shadow at all sun angles, so images during times when there is little dust in the atmosphere would be optimal.

When the SNR will be poor because it's so dark.




It isn't.



After a decade of seasonal frost crushing?

If you didn't know where PHX was....could you find it in the pictures taken a martian year after landing? Now make that 5x worse. I doubt it'd be visible at all.

Clearly there would be some optimal balance between solar angle and optimal shadow SNR, as a function of atmospheric dust load. It seemed to work rather well on the low albedo lunar surface, I'm not sure how that compares with the lower insolation on the higher albedo Mars in combination with scattering from atmospheric dust.


Clearly there is a blend of topography, some regions rather flat, others less so.


Good question. I don't know. Possibly this completely invalidates the notion. Has it been modeled?


Definitely more challenging considering the additional dust cover and crushing. On the other hand, the combination of a suggestive spike of shadow from a recent low solar incidence angle image, with a clearer image from the original search campaign, might be sufficient to firm-up an identification.

I don't have all the answers. It may or may not be worth doing, which I why I put it out there for (ideally, constructive) discussion.