The SR2 dictates it's from the super resolution camera, bolted on to HRSC, and thus suffers the same issue I mentioned previously.

Doug

I tried running Helicon Focus software on a few images. Looks like a combination of motion smear + out of focus, but the dominant effect seems to be motion smear. Due to the jpeg artifacts it's a little difficult to do a good job of this, but here are some images with the motion smear (somewhat) corrected. I think that if I had uncompressed versions of the images then I could pull quite a bit of fine detail from them.

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I don't think it's motion smear, more like noncircular PSF due to out of focus deformity in some part of the optics. It gives an appearance of vertical motion smear. It would probably be possible to do a proper deconvolution if we knew the PSF exactly (say by imaging a star), but as I recall the amount of defocus isn't constant either.

It certainly is not motion smear, but it does look like it because there is a 'double exposure' effect. Regardless, they are still nice images in other respects, and are being used to improve the shape model of Phobos (The other HRSC images are less useful for that because they are from a scanning rather than framing camera). The top one just above is inside Stickney. These pics come in sets of 4 or 5 making up strips across the surface, and would make nice mosaics.


Phil

Click to view attachment

'Double exposure' effect.
Orbit 3196, Deimos, image h3196_0005_sr2.
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Orbit 3802 - images h3802_0003_sr2, h3802_0005_sr2, h3802_0005_sr2
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Orbit 3802 - image h3802_0000_s12
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I'll take your word on that. Incidentally, what is "PSF"?

the S12 image is pushbroom.

PSF = Point Spread Function. i.e. the contribution of surrounding pixels to the pixel in question. With accurate info on that, you can subtract it all back out again..ish...roughly.

Doug

Here is a quick attempt. There does seem to be motion blurring in some of the data, almost as if it is a double exposure with one of the two slightly smeared in a direction almost but not quite perpendicular to the direction of the double exposure offset.

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Edit: The bit of motion blur I mentioned could also be explained by optics being slightly out of alignment. Normally, the difference between the two is obvious, but this is too slight for that.

i am wondering the nature of these phobos and deimos releases… are these just additional images they captured last year but we just hadn’t seen them until they released the full sets of data?

They were, for the most part, not in official releases, but were in the raw data release. Much of this has been available via ESA's PSA for a long time.

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oh, the sudden activity in this thread lead me to believe this was a new batch of materials.

are the full “global” views posted here composites that some of you have stitched or are they just full views snapped by MExpress?

Mars Express to rendezvous with Martian moon
http://www.esa.int/SPECIALS/Mars_Express/SEMVGAWIPIF_0.html
16 July 2008
Scientists and engineers are preparing ESA’s Mars Express for a pair of close fly-bys of the Martian moon Phobos. Passing within 100 km of the surface, Mars Express will conduct some of the most detailed investigations of the moon to date.

The series of fly-bys will take place between 12 July and 3 August. During the second encounter, the spacecraft will fly within 273 km of the surface. Six days later, Mars Express will close to within just 97 km.

Although the Red Planet itself has been studied in detail, very little is known about the origins of its moons, Phobos and Deimos. It is unclear if the moons are actually asteroids that were captured by Mars’s gravity and never left its orbit. Another possibility is that Phobos and Deimos are actually surviving planetesimals, bodies which formed the planets of the Solar System. They may also be remnants of an impact of a large object on Mars.

As Mars Express closes-in on Phobos, the data gathered will help scientists answer these questions.

"As it flies by at a distance of 97 km, Mars Express will image areas of Phobos that have never been glimpsed before. "

... by Mars Express. The whole surface of Phobos was imaged by Viking.

Oh for a Deimos encounter.... there's a world we really do need new images of.


Phil

Yes, particularly the trailing hemisphere.

And some people got offended when I mentioned the ESA tendency towards "little lies"?

If it ain't exactly the truth... *sigh*...

-the other Doug

Does anyone know when those images from the 97 km flyby will be made available?

Uh.... <Ahem!> Well, um...that's a pretty good question, and all I'm gonna say.

Agustin Chicarro (project scientist) told me they were supposed to be downlinked Friday, and that there should be some images released on Monday.

--Emily

00.12... bye bye Monday...

Maybe tomorrow...

He said Monday, but he didn't say which Monday

AAAhhh! Ha ha! They tricked us! =P ...

Hungry, just so you know (if you don't already), releases from ESA can be a bit erratic for a whole lot of known and unknown reasons that I definitely don't want to get into for reasons of forum decorum and that have been extensively discussed previously. Gotta wait & hope, is all.

Oh yes, I'm certainly aware. ESA's public relations has always been a source of agitation for me.

I think I've heard perhaps two or three bits of news from Venus Express in it's whole mission. I've seen perhaps two pictures from the mission.

You'll find lots of company here, then...

Just heard back from the ESA Media office...

"We are still waiting for the material, but expecting to receive the first images by the end of the day or tomorrow.

We will publish them on the web (link below) as soon as possible (tomorrow or Thursday the latest).

http://www.esa.int/esaSC/index.html"

unnecessary quoting removed

Thanks Stu,

I was beginning to wonder also. Does anyone know what the resolution of the images at closest approach will be, 1 metre per pixel, better, worse? Hopefully we'll get some more insight as to where Phobos camefrom.

Captured type D asteroid?

Formed around Mars?

Formed from impact ejecta from Mars?

My bet is still option 1, despite the difficulties with explaining orbital mechanics, but I still think, Phobos is as alien to Mars as the spacecraft we have sent.

It will be interesting to compare the new Phobos imagery with the NEAR / Shoemaker spacecraft imagery of similar resolution of asteroid 433 Eros.

Perhaps Mars Express could do similar with Deimos? Comparisons with the MARSIS & multispectral imagers / spectrometers of the two would be most fascinating.

Andrew Brown.

Using spice kernels (for the spacecraft, Mars and Phobos) I tried to simulate the Mars Express Phobos flybies.
Underneath the images of how Phobos would approximately look like at closest approach.
The field of view in these images is 30 degrees (I don't know what field of view Mars Express has).

17 july 2008 (273 km)
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23 july 2008 (97 km)
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28 july 2008 (361)
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I wonder how accurate Celestia will be

width of the HRSC swath is about 12 degrees - covering 5000ish pixels.

Doug

A photo of Phobos quoted to have been made during the 93 km flyby last week was published
in the Nature & Science section of todays Frankfurter Allgemeine Zeitung, a major German newspaper.
G. Paul, who is frequently writing about space topics there, gave some general information about
the moon and a hint, that the photos cover the proposed Phobos-Grunt landing site.
This might be an indication that some release of data is near.

Best,
Oliver

If I read that correctly, the headline says "Over Mars: A Cosmic Potato Named Phobos"? Hilarious!!!

Yes, the translation of the title is correct .

So can we nickname Phobos-Grunt "SPUDnik?" *ducks*

Link to DLR site of the Phobos Grunt landing site.

Images appearing now.

Andrew Brown.

Here is the link to the press release:

http://www.dlr.de/en/DesktopDefault.aspx/t.../86_read-13161/

The image they provided there looks pretty distorted (The 3.74 Mb image). Do they intend to clean that up?

I don't know about distortion -- Phobos looks pretty distorted in general; I can tell you from experience that it can be really hard to tell whether you have an oblique perspective or if an image has been unequally stretched. But I have a different question. There are two image releases that lack annotations. I thought that maybe they were the two views that had been combined to create the stereo image. But it appears that they are in fact the same image, stretched differently, and it seems that there was a gap in the image, some kind of data dropout, that was handled differently between the two images. In one the gap was closed, making an obvious seam; in the other, the gap was filled by duplicating pixels. I think that's what's going on anyway -- do others agree? The two pictures are
http://esamultimedia.esa.int/images/marsex...os-Flyby_H1.jpg
and
http://esamultimedia.esa.int/images/marsex...os-Flyby_H1.jpg
Odd.

--Emily

The opposite of a usual activity: take apart an anaglyph to get its separate frames and voila, two more HRSC images of Phobos. Here's the red channel:
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And the blue channel:
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Enjoy!

--Emily

Interesting, the relatively small number of the tiniest craters. The dust layer must be mighty thick.
Really cool anaglyph on the home page - it really leaps off the screen at you!

I just had a really dumb idea, looking at that moon again. I was noticing how much it resembled the rocks around Opportunity at Victoria, and I started thinking...Hmm, what if those grooves were caused by differential micrometeoroid weathering due to layers? They do resemble at a macro scale the aeolian cross bedding we've seen before. That would add weight to the "Phobos is a chunk of Mars" idea!

The best (for me) explanation I've heard for the grooves so far was highlighted by Emily over at TPS as being the result of Phobos sweeping up ejecta in chains from Martian impacts. Scroll down on the linked article to see a computer simulation which is a good match to the observed grooves.
But looking at the latest pictures, they seem to be far too straight and of regular width to be secondary crater chains - looking much more like collapse features to my untrained eye.
The mystery remains....

In Astronomy & Astrophysics: New astrometric observations of Phobos with the SRC on Mars Express

Mayby grooves on phobos seem not to be due to secondary impacts from asteroid impacts on Mars; they are too defined and regularly for that. These computer simulations seems to give only the trajectory of the ejected masses but the the width of the shower. And there are too much of these grooves and they are too regularly placed. This counts for some effects connected with material resistance against stress forces per length unit.

Especially, one set of grooves seems to be more or less concentric or better: coaxial along the Mars-anti-Mars-axis and can be explaned easily with tidal effects. The "craters" along the grooves may be simply sinkholes, especially because there are no ejecta. The other set of grooves (here highlighted in red) is nearly perpendicular to the other one and can be formed earlier by the same way; a large impact may have altered phobos orientation by chance and after that tidal fractures occure in a new set. So, that older bunch of grooves is orientated around the old Mars-anti-Mars axis of Phobos. Here:

http://www.planetary.org/blog/article/00001391/

or here

http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2195.pdf

You can see the both sets, but you need another cartographic projection to see the old set as a concentric/coaxial one as well as the other.

Both groove sets are not (the old one) or not well (the new one) converging to two points but slicing phobos more like a cut potato. Here, the non-sperical shape of phobos and cartographic problems with this fact should be considered; the pseudo-convergence is an articfact of the cylindrical projection!

I would also consider that Phobos had been in an elliptic orbit first, so diffential stresses du to the tidal force change between apoareum and periareum and libration (nodding) effects due to the constant rotation period and the inconstant orbital angular velocity would have forced a result. A large impact, mayby the Stickney forming impact, would have altered the meanwhile circular orbit to an elliptic one again and it altered Phobos spin and orientation. So a second set of grooves came to existence.

You may recognize that the younger grooves, which are mostly sharper defined and smoother than the older ones (red) cross through them (and not opposite) which will give a hint which groove set was the former one.

The Stickney-impact itsself may be "buffered" by the weak material itsself, like the craters on asteroid Mathilda, and does not harm the whole structure. It is like shooting a projectile in styrofam...

It would be interesting to look for some grooves on several other moons like Amalthea; in the Saturnian system so much dust maybe hide features like that on the innermost moons.

The "new obervations" reported don't include the recent batch of observations discussed here. The most recent observation in the article is dated 2007-02-25T02:44:11.994

The main concern is with the fine details of Phobos' orbit.

Steve M

Interesting article about Phobos on the ESA website, based on the recent flyby:

ESA closes in on the origin of Mars’ larger moon

In the article just quoted by charborob, there is an animation of Mars Express being diverted from its orbit during a close pass by Phobos. The interesting thing about this simulation is the way MEX returns to its original orbit after the deviation. It looks kind of like the maker of the simulation has added the symmetric plot of a normal distribution to the original unperturbed track of the spacecraft. Is this really how it would happen, or would the spacecraft experience a permanent change in its orbit due to the small gravity assist derived from Phobos? Observatoire Royal de Belgique must know a lot more than most of us about orbital mechanics, but maybe in this case they are pulling our legs and expecting us not to notice?

I checked "forgotten" Mars Express archive and I stated that this year Phobos has been photographed several times. Unfortunately, the quality is not stunning.
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and Phobos over Mars craters.
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I like the last two transit images! More close passes would certainly be nice, especially if they showed the Phobos-Grunt landing region better.

Phil

Transit image modified to show the Martian surface better.