Thanks... I may get around to something eventually, but my attention is mainly on past landing/impact sites and Mars at the moment.

I expect the LROC team will produce WAC mosaics of areas of interest like the poles, and NAC mosaics of the Constellation Regions of Interest which include the poles, fairly soon.

Phil

the pols are very "fun" to work on
when i remapped the clem map i had to use some of the Kaguya DEM to fill in the Clem images

the poles are a pain in the ( you know what) to work on

how much do you want to bet that everyone will " let someone else do it" and there wont be any .

No way! Did you see the WAC mosaic of Orientale? We'll have that for the whole Moon as a new fundamental basemap. And the poles are both 'regions of interest' and will be fully mapped with stereo NAC, Diviner, LOLA etc. The mapping products wil be amazing. But the mission is still in progress so data gathering takes precedence. One other point, LOLA will be the new basic positional control system, and until that data set is complete no serious mapping will be done, only test products.

Phil

Found this the other day and was surprised I did not see it before now.

A nice image of apparently the floor of the pit of the Marius Hills pit / Lava Tube Skylight.
I find the image kind of creepy.

Click to view attachment

http://wms.lroc.asu.edu/lroc/view_lroc/LRO....0/M122584310LE


The pit had originally been shown at a different sun angle on
http://lroc.sese.asu.edu/news/index.php?/a...e-Skylight.html

Click to view attachment

Very nice - thanks!

Phil

More on pit craters here:
http://lroc.sese.asu.edu/news/?archives/25...it-Craters.html

I found an extra image that had not been reported elsewhere of the Mare Ingenii pit/cave/skylight/lava tube.

Here is the publicized Mare Ingenii image.

Click to view attachment

http://lroc.sese.asu.edu/news/index.php?/a...i.html#extended

Here is what I found on my own and which I have not found posted elsewhere.

Click to view attachment

Here is an overlay (somewhat poor) of the two.

Click to view attachment


Also, for the previous Marius Hills unpublished image I found, I created an overlay image.

Click to view attachment

Nice work!

It sure fires the imagination to speculate about what it might be like down in there.

Dark... really really dark!


Sorry, couldn't resist!


-- Pertinax

Stark and unforgiving, mighty cold, airless, lifeless and dusty, but nevertheless phenomenally beautiful...

check it out

Edit: the Bhabha close-up I mean - worth looking at the high-res version. Simply breathtaking!

Check out today's LPOD for news on software for extracting LROC wide-angle images from the multispectral data:

http://lpod.wikispaces.com/September+1%2C+2010

Phil

Keep checking LPOD - more news on LROC Wide-Angle processing several times this week. Like IMG2PNG and Midnight Mars Browser, we're seeing a valuable service being provided by members of the distributed community of data users. (PS Chandrayaan data release now set for the end of the year - I hope it includes all the MIP images)

Phil

Thanks to Emily for featuring this natural bridge discovery:

http://www.planetary.org/blog/article/00002652/

((I guess the challenge is on for the HiRise team to catch some oblique light passing through the one they found on Mars.))

There's a spectacular new WAC mosaic of the Moon centered on longitude 90 degrees. It's in orthographic projection, so the limb is smooth rather than lumpy. I would love to be able to take this orthographic projection, fill in the gores with a more neutral gray, then drop it on top of the Kaguya or LOLA topography data to make a more natural-looking image, but I don't know how to do that last step. Is this something I should be able to do with some software tool like Celestia? If so, is there anyone out there who could talk me through how to do that?

Converting from orthographic projection to equirectangular (for Celestia et al) is probably not something that's particularly easy, nor is it likely to produce good results. (I've contemplated it in moments of desperation.) Odds are they already have an equirectangular product and will release it when they're good and ready.

Edit: I should say, I don't know if anyone has created a tool to do it. I wrote some custom code to do it once. Either way, it's not likely to be a good result.

On the other hand the topo might be projected into orthographic without too much trouble!

Phil

hay soon i will be able to replace the remapped Clementine map( fitted to LOLA ) with a new one .

Good point Of course the real trick either way is to get them to line up.

We had some discussion in the past - of course now I can't see it, and don't have time to search - about telling if LROC images are reversed or not. It occurred to me that the answer should be in the coordinates listed in the image data panel or label.

Like this from M119862875RE:

Sub solar longitude 304.58
Sub spacecraft latitude 0.41
Sub spacecraft longitude 358.32
Solar distance 147630581.9
Solar longitude 25.74
Center latitude 0.41
Center longitude 358.35
Upper right latitude -0.07
Upper right longitude 358.39
Lower right latitude 0.88
Lower right longitude 358.38
Lower left latitude 0.88
Lower left longitude 358.31
Upper left latitude -0.07
Upper left longitude 358.32

If you check out the upper and lower corner latitudes you find that upper is -0.07 and lower is 0.88 (where - = south latitudes) - so it's flipped N-S.

If you look at the longitudes, left is less than right, and these are east longitudes (it helps to know that! But people, please, always specify!), so it's NOT flipped E-W.

But if you do a 180 degree rotation to put N and S where they should be, it will now be flipped E-W!

At any rate, the labels should tell you.

Also for images with the sun NOT overhead: the subsolar longitude will be east or west of the image (in this case it's west of the image, at 304 E). So if you put N and S where they should be, the shadow direction will tell you if any E-W flip is needed.


Phil

This is an unusual feature just to the NW of Prom. Laplace at about 48.5 N, 22.7 W in northern Mare Imbrium. The LROC image number is in the filename if you save it.

The area is typical mare except for the roughly circular area with a wrinkly texture. At first sight it looks like the textures seen on most lunar slopes, for instance the Flamsteed hills near Surveyor 1 and many areas near the south pole, and attributed to downhill movement of the regolith. But this is not a hill. Even under this very low angle illumination it looks flat or possibly slightly depressed. The crater density within it looks lower than the surroundings, though I have not done a careful count. Objects like Ina (D-Caldera) are sometimes attributed to outgassing through the regolith. In fact I was looking for exactly that kind of feature when I found this (because of a curious marking near here in the LROC WAC mosaic currently featured at the LROC site). Could this be a less well developed version of that kind of feature?

Phil

Click to view attachment

For what's worth, my home made shape-from-shading code came up with this:



Dark = Low, Bright = High


The feature seems complex and perhaps with a double ridge.

That is completely strange. Looks like an impact feature generated by a puffball...

Well spotted!
John

Heh, this reminds me. I have heard about comets and other icy/watery objects being responsible for some of the water on the Moon (and Earth for that matter). Could this be an impact site of this sort of object? Or would they appear no different than a rock at the speeds they are travelling? Depends on the object densities I guess.

Also, the LOLA data has some heights very close to that longitude/latitude.

Most hypervelocity impacts of even fluffy comet nuclei would be expected to make a crater, I think.

Phil

Most is correct. But what about those going the same direction as the Moon? I seem to recall meteors hitting Earth had some better chance of survival in those cases.

You're still going to fall into the gravity well and hit at very high speed. If you were hovering magically 1000km above the moon, then just fell to the moon under its own gravity - your impact would still be at about 1.4-1.5km/sec

I was thinking of a large number of dispersed small impactors impacting over an area comparable to the size of the feature. If small and numerous enough, you might get a disturbed area that looked like this. But I'm not saying such a thing is very likely. A disintegrating comet, for instance, might have a cloud of small particles but would probably include some large chunks which would produce a bunch of discrete craters in addition to the generally disturbed region. The cloud of particles would also have to be very tightly confined somehow. So I'm still baffled...

John

Probably wrong, but... what if this is a deep magma chamber collapse? Should look like chaotic subsidence on the surface...

if we are going to toss out "odd" ideas
it looks like a California hill side after a bunch of small mud slides

so
the cause : landslides after some moon quakes

but seriously it would be possible for some of the regolith to have shifted after local recent impacts

I follow why it is very unlikely to be a very low speed (<1km/sec) fluffy icy comet nucleus.

However, I did find an interesting paper which ran simulations on various cometary nucleus densities.

"Cometary and Meteorite Swarm Impact on Planetary Surfaces"; John D. O'Keefe/Thomas J. Ahrens; Seismological Laboratory, Division of Geological and Planetary Sciences California Institute of Technology; Journal of Geophysical Research, Vol. 87, #B8, pg 6668-6680, 1982.

They looked at densities of 1, .1 and .01 gm/cm^3. For 1 gm/cm^3 at 5-15 km/sec, the solid ice impactor presents a crater that appears like a solid silicate impactor. At 0.1 gm/cm^3, the crater is more like a disc at 5 km/sec and ring at 15 km/sec.

They state the depth/projectile diameter ratio is about the same for 5km/sec and 15 km/sec. For the maximum depth of the surface undulations, for 1 gm/cm^3, this ratio is about 1.5. For .1 gm/cm^3, the ratio is about .5. For 0.01 gm/cm^3, it is about 0.08. Thus for very low density impactors, "the mean of the excavation depth is near zero". Most of the .1 and .01 gm/cm^3 cases had flat floored craters and some with surface instabilities.

Pretty neat work for those days.

Not clear how frequent the impactor events are or what the current thinking of comet nucleus density is. Louis Franks had a rather large frequency for small comets which caused a bit of controversy.
Click to view attachment

Anyone find any interesting LROC images lately? Are we all bored of boulder tracks and cave pits by now?

I saw this odd feature today which I can't figure out.

http://wms.lroc.asu.edu/lroc/view_lroc/LRO....0/M126452243LC

Just a lucky crater wall slide or some collapsed dome? Kind of hard to figure out the shadowing. I would have thought the inner ring lower than the outer rim, but then why is the ring unshadowed?

Click to view attachment
Image at 195% of original.

It's a result of the illumination angle. The sun's elevation and the slope of the crater are near enough to each other that the sun will illuminate features sticking up out of the slope of the crater (in this case, the ring).

I have noticed for the high latitudes such as shown in this image, but also apparent in lots of other such images, that there appear to be lines or furrows or shadows in one direction. Is this another kind of optical illusion? The lines do not seem to be in the direction of the sun.
Click to view attachment
http://wms.lroc.asu.edu/lroc/view_lroc/LRO....0/M127825115RC

My question would be why are all the craters elliptical/squashed? Looks to me like a vertically squashed image and as a result giving rise to horizontal "lineations" in the terrain.

Good point. The data for the image says it is .42 m/pixel for width and 2.18 m/pixel for height. Adjusting the image gives the following...
Click to view attachment

It still looks like lines are there.

Really unusual lunar rock with a diameter about 320 meters
http://lroc.sese.asu.edu/news/index.php?/a...r.html#extended
Strange that such a huge block remained intact.

I see a hole but no block. I guess the hole implies that the block is somewhere. They seem to say it plopped back down and got covered by some sheet of material. I can't figure how they can deduce that.

Your eyes are playing tricks on you. It is in fact a block, not a hole. Keep looking at it: eventually, your brain will invert the relief. It's the same phenomenon that makes you see round mounds instead of craters.

I could also interpret it as a slump block, mostly consisting of melt or breccia cemented by melt, possibly undermined by a slump under it, and maybe only having moved a few meters or tens of meters.

Phil

That's funny but you are right!

Sorry about the repeats. Something wrong with the server I think.

This is the Marius Hills lunar pit/cave/lava tube image I found on July 16 but which was posted September 14 at the ASU website:
http://lroc.sese.asu.edu/news/index.php?/a...Lunar-Pits.html

Click to view attachment

http://wms.lroc.asu.edu/lroc/view_lroc/LRO....0/M122584310LC

In the latest batch of images from last week, they apparently captured a slant image of the same cave. From:
http://lroc.sese.asu.edu/news/?archives/25...it-Craters.html
"The LROC team will acquire images at a slant attempting to look for overhangs that might indicate the lava tubes are still open and accessible."

Click to view attachment

http://wms.lroc.asu.edu/lroc/view_lroc/LRO....0/M137929856RC

Here we can see the wall of the cave and a peak under the overhang.

Thanks to Robert Zimmerman for getting me to correctly interpret this image.
http://behindtheblack.com/behind-the-black...to-a-lunar-cave

An interesting site I had not heard about is called Moonzoo (http://www.moonzoo.org/) which seems to have the public look for interesting things in LRO images. Any other similar sites out there? Be nice if the LRO folk sponsored or had such a site.

One interesting type of image is introduced there... http://forum.moonzoo.org/index.php?topic=269.0

Specifically it is called "boulder repellent" and is an odd aspect of a flat area at the bottom of a boulder strewn crater. Pretty weird in my book. Looks almost faked.

Click to view attachment

Nice image! I'd say it was simply an extremely fresh impact crater with a melt pool in the bottom- the melt pool apparently didn't freeze until after the walls stabilized, so any boulders that rolled down disappeared into the melt. It's fresh enough that no subsequent impacts have dislodged any boulders down onto the frozen melt pool since then.

John

Another interesting LRO striated rock/boulder image from the Moonzoo site.

Click to view attachment

Location: Aristarchus.
Latitude: 24.2409°
Longitude: 312.927°
Sun Angle: -55.76°
Scale: 0.51 meters / pixel

http://wms.lroc.asu.edu/lroc/view_lroc/LRO....0/M111904494RE
http://forum.moonzoo.org/index.php?topic=195.msg6006#msg6006

Theorizing on the website was that it was due to volcanic eruptions.

Good... grief...

Oblique view of Aitken Crater... http://wms.lroc.asu.edu/lroc_browse/view/M149411565LE

Looks like some of the folded features that were talked about a press conference or two ago.

Without a doubt, we need speleologists.
http://lroc.sese.asu.edu/news/index.php?/a..._void!.html
Wow (second time today).

Nice Zoomify for the nearside!
http://lroc.sese.asu.edu/news/index.php?/a...cular!.html

It's pretty awesome! Google Moon has new competition!
Now for the far side...

And now the far side
http://lroc.sese.asu.edu/news/?archives/34...way-around.html