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| LROC Narrow Angle Camera (NAC) "footprints" narrowed to those unprecedentedly low (25 km) altitude observations gathered last August, seen here in Google Earth. |
Lunar Pioneer
Since the 8th 'tri-monthly' Data Release by teams flying instruments on-board LRO on December 15 we've been rushing to sample the latest set of LROC Narrow Angle Camera (NAC) footprints to discover what's new.
After downloading the newly-updated NAC and WAC footprint KML's for viewing with the Google Earth program (through the Planetary Data System (PDS) the first temptation is to try to take it all in. But that's like examining every square nanometer of a basketball with a microscope. So we tried, once again, to begin instead by taking note of new NAC observations of our ever-growing list of favorite targets.
And yet, this latest release was more highly anticipated than any since the Commissioning became the Nominal LR mission in late 2009. Before being redeployed to a more fuel efficient higher orbit in January, last August flight directors reduced the spacecraft's orbital perilune to within 25 kilometers for a brief time. This made possible an even closer examination of three of the six Apollo landing sites, the subject of a NASA news conference in September.
What wasn't generally discussed at the time, however, was what else might have been photographed at 40 centimeters per pixel resolution and greater last August.
After downloading the newly-updated NAC and WAC footprint KML's for viewing with the Google Earth program (through the Planetary Data System (PDS) the first temptation is to try to take it all in. But that's like examining every square nanometer of a basketball with a microscope. So we tried, once again, to begin instead by taking note of new NAC observations of our ever-growing list of favorite targets.
And yet, this latest release was more highly anticipated than any since the Commissioning became the Nominal LR mission in late 2009. Before being redeployed to a more fuel efficient higher orbit in January, last August flight directors reduced the spacecraft's orbital perilune to within 25 kilometers for a brief time. This made possible an even closer examination of three of the six Apollo landing sites, the subject of a NASA news conference in September.
What wasn't generally discussed at the time, however, was what else might have been photographed at 40 centimeters per pixel resolution and greater last August.
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| Most of the full width of LROC Narrow Angle Camera (NAC) observation M168570575R, orbit 9976, August 21, 2011; incidence angle 37.14° with an original resolution of 0.3994 meter per pixel from 23.98 kilometers. The white rectangle is the smaller field of view shown at the original resolution in the image immediately below. At this low altitude, where LRO was flown for only a brief time last August, it's necessary to step back quite a long way to appreciate the context, in this case a north-south 1000 meter-wide cross-section of the unofficially named "Sinuous Rille A" feature in the Marius Hills region of Oceanus Procellarum [NASA/GSFC/Arizona State University]. |
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| The boulder-shedding southern edge of "Sinuous Rille A" as viewed from only 24 kilometers above on August 21, 2011. The original layering of the the surrounding greater Procellarum basin as excavated by more "recent" flows from the Marius Domes is clearly exposed. The smallest features distinguishable are only 40 centimeters in size. The first of the "pit craters" discovered on the Moon here by Japan's Kaguya orbiter team in 2009 is located elsewhere on the floor of this rille. (Field of view only 230 meters) [NASA/GSFC/Arizona State University]. |
To appreciate the volume of data in dire need of crowd sourcing the basics are worth repeating: According to the December 22 announcement, by LROC investigator Ernest Bowman-Cisneros, "(t)he 8th LROC Planetary Data System (PDS) release includes images acquired between 16 Jun 2011 and 15 (Sept.) 2011" including "83,010 EDR images totaling 8.5 Tbytes and 83,010 CDR images totaling 17 Tbytes... To date, the LROC team has released a total of 586,217 images (EDR) totaling 64.7 Tbytes. The complete LROC PDS archive can be accessed via the URL http://lroc.sese.asu.edu/data/."
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| Context: Color LROC WAC Digital Terrain Model (DTM) 64, showing the location of a massif pictured below, just outside the central ring of mountains surrounding the deep interior basin of Mare Orientale. The area was imaged at unusually low altitude by both NAC and WAC LROC cameras last August, around the time of the now-seasoned orbiter's unprecedented 10,000th orbit around the Moon [NASA/GSFC/Arizona State University]. |
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| The LROC Wide Angle Camera (WAC) was along for the ride last August, when LRO's orbit was briefly lowered to within a 25 kilometer perigee. On August 21 LROC swept up this 4000 meter-high massif just beyond the northeastern interior of Mare Orientale (9.5°S, 91.64°W), seen here in a mosaic at 604 nm from three sequential passes averaging 33.4 kilometers above. The resolution averages around 48 meters per pixel [NASA/GSFC/Arizona State University]. |
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| A bit of cutting and pasting allowed the filling in of this LROC NAC footprint (M168808506L and R) in three dimensions. The area within the white square is detailed below [NASA/GSFC/Arizona State University]. |
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| The very steep slope of the unnamed massif blown up to 2 meter per pixel resolution does little justice to the original. LROC NAC M168808506R, orbit 10011, August 20, 2011; illumination incidence angle 32.96° with a raw resolution of 44.2 centimeters per pixel from 33.2 kilometers [NASA/GSFC/Arizona State University]. |
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| At full resolution, the boulder and it's interrupted trail down the south face of the massif show signs of space weathering. It's by no means the most spectacular feature in the August lower altitude NAC frames [NASA/GSFC/Arizona State University]. |
There are boulder trails, to be sure, and though it may be only our imagination but there seems to be more than a random share of small, bright impact craters in the set. The best candidate for the impact crater formed by the Apollo 15 lunar module ascent stage, for example, was swept up yet again. As we begin to sort out our notes in greater order we look forward to posting better examples from this unique set. Like every other lunatic following LRO's steady progress we look forward to seeing and reading what Robinson's LROC team at Arizona State has uncovered in these frame also.
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| Now that's an interesting boulder trail! From only 23 kilometers overhead, a chunk of ring-bound upthrust the size of a passenger trail locomotive has rolled down and pitted this shallow incline near the dead center of Mare Serenitatis. The August "close-up window" enjoyed briefly by LROC's NAC system seems to have had its advantages centered on the nearside longitudes and just beyond either limb. LROC NAC M168081909R, LRO orbit 9904, August 15, 2011; incidence angle 46.74° with a resolution of 39 cm per pixel from 23.06 kilometers [NASA/GSFC/Arizona State University]. |
LRO sweeps down for a closer look at Apollo sites
August 13, 2011
Low-altitude views of Apollo released
September 3, 2011
LRO Briefing: Latest close-ups of Apollo sites
September 6, 2011
Skimming the Moon
New views of Apollo 12
Apollo 14 at 25 cm per pixel
On the rim!
September 8, 2011
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