Tuesday, August 21, 2012

NASA awards funding for sub-surface exploration by Astrobotics, among 28 needed innovation studies

Close-ups of the Tranquillitatis pit crater (8.337°N, 33.219°E), LROC Narrow Angle Camera (NAC) observation M155016845R, LRO orbit 7979, March 17, 2011. The interior is seen under a high Sun (incidence angles around 10.58°) and at resolutions close to 47.4 centimeters per pixel, from 39.67 kilometers. LROC QuickMap link [NASA/GSFC/Arizona State University].
Astrobotic Technologies has announced a contract with NASA to develop technologies for exploring caves on the Moon, Mars, and beyond. Astrobotic was one of ten teams to be selected for phase II awards from NASA's Innovative Advanced Concepts (NIAC) program.

NASA also announced funding for 28 innovative programs under the NIAC label.

Planetary caverns and tunnels can provide shelter from micrometeorites, radiation, and thermal extremes for human and robotic explorers. They may be the best hope for habitation on the Moon. They could be the best place on Mars to find life. They can provide a window into a planet's past geology, climate, and even biology. Recently discovered skylights, formed by partial cave ceiling collapse, provide access to sub-surface voids. In a phase I study for NASA's NIAC program, Astrobotic developed several mission concepts and investigated key technologies for exploring these exciting planetary destinations.

In phase II, Astrobotic will detail a mission concept for entering a planetary cave through a skylight, and exploring and modeling the interior. "Skylights are gateways to wonders of exploration, science and resources that await beneath planetary surfaces", said Red Whittaker, Astrobotic CEO. "Robots are our access to those new worlds." Robotic technologies will be developed to explore the extreme terrains of skylights and caves. This is very different from surface exploration, as has been achieved on the Moon and Mars. Technologies will be developed to descend into the holes, negotiate the blocky floors, and thread into the tunnels. The company will also roadmap technology for future planetary cave exploration missions. Astrobotic will collaborate with experts in subterranean robotics at Carnegie Mellon University on this contract.

Saturday, August 18, 2012

LROC: Fresh crater in Komarov's fractured floor

A fresh crater splashing ejecta across the edge of a fracture in Komarov crater. Field of view is 2.5 kilometers, from LROC Narrow Angle Camera (NAC) observation M191967463R, LRO orbit 13324, May 18, 2012; native resolution 1.52 meters. View the 1650 x 1650 LROC Featured Image, HERE [NASA/GSFC/Arizona State University].
Sarah Braden
LROC News System

The wispy, bright rays of this small crater (~475 meters in diameter, 24.801°N, 151.687°E) extend down into the fracture (graben).

You can see that this small crater is younger than the fracture because the bright rays of the crater are not visibly deformed by the edges of the fracture.

Gradually, cratering events like this contribute to the erosion and infilling of fractures and other craters on the lunar surface.

Komarov crater is on the southeastern edge of Mare Moscoviense and is located at 24.59°N, 152.25°E (diameter 80.43 km). The floor was long ago filled with mare basalt, and then cut with a spectacular set of intersecting fractures, or graben. Graben form when a section of the crust sinks as two parallel faults pull the crust apart. Note that the northwestern section of Komarov's rim has an irregular shape. the irregular shape is likely due to a preexisting impact crater. The older crater influenced the formation of Komarov's rim, and may have been partially flooded with molten mare material when Komarov's floor was filled in.

LROC Wide Angle Camera context image of Komarov Crater; the red box marks the total area imaged in the LROC NAC frame containing the field of view in the LROC Featured  Image. View the original LROC context image HERE [NASA/GSFC/Arizona State University].

Explore the rest of Komarov's fractures in the full resolution LROC NAC frame, HERE.

Related Images:
Alphonsus crater mantled floor fracture
Gassendi's Fractures
Atlas

Virtual view from an imaginary point 93 km over the lunar farside, south of Komarov. The LROC 302 ppd WAC mosaic draped over LOLA 128 laser ppd topography shows how pyroclastic flow overran the mare-filled Moscoviense floor. Both the famous long floor and Komarov are each well inside the larger, circular and less obvious Moscoviense basin [NASA/GSFC/LMMP/Arizona State University].

Thursday, August 16, 2012

LROC: Melt pit on the floor of Louville D

Fractured impact melt with a probable impact melt pit inside the crater Louville D. LROC Narrow Angle Camera (NAC) observation M170897609R, LRO orbit 10319, September 17, 2011; resolution 0.5 meters from 45.36 km [NASA/GSFC/Arizona State University].
Sarah Braden
LROC News System

Louville D is a young crater, 6.89 km in diameter, located in northeastern Mare Procellarum (46.85°N, 52.13°W), near Sinus Roris.

The Featured Image shows a group of fractures and one possible pit (center of image) within the impact melt at the bottom of Louville D.

How do we determine what is a possible impact melt pit and what is a shadow from a boulder? The most important source of information on this is multiple images at different viewing angles.

For instance, in one image the Sun is low in the sky and many shadows are cast due to crater rims, boulders, and fractures. In a different image with the Sun high in the sky there are almost no shadows. In this high-sun case, pits are extremely visible as dark areas that reflect very little light back into space. High-sun images result in an unambiguous identification of a lunar pit. But what happens when we do not have a high-sun image of a potential pit?

A smaller-scale image from LROC NAC M170897609R show the floor of Louville D in context with the contact zone with the 6.89 km-wide crater's walls [NASA/GSFC/Arizona State University].
While looking at an image with many shadows, it may be unclear if an area is a shadow or an actual pit in the impact melt. Most of the time you can see the boulders well enough to match a shadow to the corresponding boulder, but sometimes the boulders or the topography can be hard to see. A handy trick is to look at the amount of light in the dark area. In most cases, there is enough light in shadows for LROC to detect. This light is reflected into the shadows by surrounding objects. However, less light can reach the inside of a pit, and LROC will detect overall less light in pits.

LROC WAC context image of Louville D with Rima Sharp to the east. The full-size Wide Angle Camera mosaic field of view 100 km [NASA/GSFC/Arizona State University].

Explore a closer look at this possible impact melt pit and the floor of Louville D in another full resolution NAC frame (M142604009R), HERE.

Related Posts:
Impact Melt Pit
Natural Bridge on the Moon!
Sublunarean void 
A view of Rima Sharp and Louville D and Louville DA from the north from a Planetary Camera image captured by Japan's lunar orbiter SELENE-1 (Kaguya) [JAXA/SELENE]
There's a lot more natural history engraved on this area of the lunar surface than meets the casual observation, shown by the USGS, reduced from USGS Rumker I805 [USGS].

Tuesday, August 14, 2012

LROC: Giant flow of Tycho impact melt

This giant fossilized glacier of impact melt extends north from a much larger mass of impact melt of the north rim of Tycho. This single section of the flow is more than 10 kilometers long. LROC Narrow Angle Camera (NAC) observation M185954551R, LRO orbit 12482, March 9, 2012; resolution is 0.6 meter per pixel of a 43.53° angle of incidence, from 64.8 kilometers altitude. View the larger LROC Featured Image HERE  [NASA/GSFC/Arizona State University].
Jeffrey Plescia
LROC News System

Impact melt is formed during the crater excavation process due to the intense heating of the target rocks. Some of the melt is ejected from the crater and deposited on the rim. In this case, on the north rim of Tycho, not far from the Surveyor 7 landing site, a large amount of melt was deposited, pooled and then flowed downslope away from the crater. This flow (41.162°S, 348.605°E) is about 21 km from the northern rim. Upslope, toward the rim, there are also numerous smaller pools of impact melt (now frozen to solid rock). Contrast this flow with the River of Rock on the southeast side of Tycho crater.

From a half-sized reduction of the original LROC context image (HERE), this expanded view of the full LROC frame (NAC M185954551R) shows more of the flow anatomy, extending north from Tycho. The white box shows the field of view included in the featured image above [NASA/GSFC/Arizona State University].
This giant frozen flow is more than 10 km long! When the flow emerged onto the plains it was about 1.3 km wide; at the terminus it spread out about twice as wide (2.7 km). Along the center of the flow is a channel with levees; the channel is about 1 km wide. In the levee walls and on the flanks of the flow are layers which formed when surges of melt spilled over onto the side of the flow. The morphology of the end of the flow, with lobes stepping to the right, indicates that with each surge, the end of the flow was directed eastward. The surface within the channel shows tension cracks that are perpendicular to the flow direction and formed as the solidified crust fractured. There are several other flows of impact melt on the northern flank, although this is the most dramatic. Impact melt also fills much of the crater floor.

Northern flank of Tycho, its wall, rim painted with flows and pools of ejecta; the arrows points to the flow highlighted above, the blue cross marks the landing site of America's last unmanned lunar lander Surveyor VII, highlighted below. LROC Wide Angle Camera (WAC) 604nm observation M152952485C, spacecraft orbit 7644, February 21, 2011; angle of incidence 57.41° at 63.7 meters resolution from 46.5 kilometers overhead [NASA/GSFC/Arizona State University].
Explore this giant impact melt flow in the full NAC image, HERE.

Ejecta on Tycho floor

The very successful and daring Surveyor 7 was successfully landed right in the middle of the complex Tycho impact melt fields, north of the crater, about 10 km away from the field of view included in the LROC Featured Image. Less than a kilometer, beyond view of the spacecraft's cameras, is s substantial melt pool, where Surveyor might easily have landed instead. LROC NAC M152952815R, LRO orbit 7674, February 21, 2011, resampled from the original resolution of 0.5 meters from 44.7 kilometers [NASA/GSFC/Arizona State University].

Friday, August 10, 2012

Barcelona Moon Team contracts with Great Wall

Long March 2C/CTS-2 booster [GlobalSecurity.org].

Great Wall Industry Corporation of China will send the Spanish Google Lunar X-PRIZE team's lunar rover to the moon in June 2014, according to the Galactic Suite company which heads the "Barcelona Moon Team" that is competing in the Google Lunar X Prize contest.

The rover will be launched by a Long March 2C/CTS-2 rocket from China's Xichang Satellite Launch Center. The Google Lunar X-PRIZE challenges participants to create a robot that can move over the lunar surface and send live images back to Earth before December 2015.

(WIRED, August 9, 2012)

Thursday, August 9, 2012

LROC: Sampling a Central Peak

Boulders originating from the central peak of Moretus crater litter the contact zone between peak and  crater floor. LROC Narrow Angle Camera (NAC) observation M185904952R, LRO orbit 12475, March 9, 2012; angle of incidence 72.71° at 0.95 meters resolution 45.42 kilometers over a field of view about 852 meters wide. See the larger LROC Featured Image HERE [NASA/GSFC/Arizona State University].
Lillian Ostrach
LROC News System

Groupings of boulders are commonly observed at the boundary between crater wall and floor, and tracing boulder trails through LROC images is always a fun pastime. However, the importance of identifying boulders with trails traceable to the boulder origin cannot be emphasized enough when considering future lunar exploration. Previous posts have mentioned the importance of the Station 6 boulder to the Apollo 17 mission because the remote sensing images coupled with the surface samples of the boulder allowed scientists to learn about the local and regional geology of the Taurus-Littrow landing site. The boulders in the opening image would tell a similar story, allowing future human explorers to sample lunar rocks that are otherwise very difficult to obtain.

"Tracy's Rock," the boulder visited at Station 6, near the third and final EVA of Apollo 17, December 13, 1972. Pictures taken by mission commander Gene Cernan of Harrison Schmitt, with a panorama of Taurus Littrow valley in the background, are among the more memorable from the program. LROC NAC observation M165645700RE, orbit 9545, July 18, 2011; resolution 47.7 cm per pixel from 40.6 kilometers [NASA/GSFC/Arizona State University].
Both left and right frames of NAC observation M184903952 are draped over the GLD100 digital terrain model and resampled at 8 meters per pixel resolution, using the LROC QuickMap web-based application, to allow a quick analysis of the boulders in the Featured Image in context with their 3800 meter trails, from the top of the central peak of Moretus to the 114 km-wide crater's floor [NASA/GSFC/DLR/Arizona State University].
Moretus crater (70.631°S, 353.977°E, ~114 km diameter) is a complex impact crater found on the southern nearside. A beautiful central peak formed during the impact process, and over geologic time, the central peak was eroded by small impact events. As the rock in the central peak fractures and breaks, pieces travel downhill. Some boulders only made it partway down the central peak slope, while others descended all the way to the crater floor. As you can see by looking at the opening image (70.541°S, 354.221°E), the boulders that made it all the way to the crater floor range in size from about 10 m to 40 m in diameter and have different shapes. Where a boulder rests is dependent on many factors that include the size and shape as well as how the boulder was perturbed in the first place - maybe a small meteorite impacted the peak at just the right angle and velocity to dislodge the boulder or maybe a nearby impact created shock waves that jiggled the boulder loose. However, because gravity is ever-present, it is probable that at some point in the future, all the boulders on the central peak slope will fall.

LROC WAC monochrome mosaic centered on Moretus crater (70.631°S, 353.977°E, ~114 km diameter). Opening image noted by asterisk [NASA/GSFC/Arizona State University].
Boulders such as these are incredibly valuable for future exploration because they represent material from the central peak (pushed up from depth during crater formation) and their origin can be determined by tracing the trails uphill. Of course, it would be a mighty feat to ascend to the summit of the central peak of a crater like Moretus, Tycho, or Copernicus; however, lunar scientists would all probably agree that obtaining samples from a wide range of geologic units and regions on the Moon holds high scientific interest and merit and is absolutely necessary.

Put yourself in a future astronaut's shoes and traverse the full LROC NAC image, HERE. Which boulder (or boulders) would you want to sample and why?

Wednesday, August 8, 2012

Scooping the Soviets

Luna 9's view of the lunar surface, the "unauthorized" version [Jodrell Bank Observatory].
Paul D. Spudis
The Once and Future Moon
Smithsonian Air & Space
  
Sir Bernard Lovell, the former Director of Britain’s Jodrell Bank Radio Observatory, died recently at the age of 98.  Lovell took the lead in establishing Jodrell Bank near Manchester – one of the world’s premier radio telescopes, a facility that played a lead part in the history of the early space age.  One of its most memorable episodes was its role in releasing the world’s first images taken from the surface of the Moon.

In late January 1966, the USSR launched the probe Luna 9 to the Moon.  The Soviets had tried to soft-land a spacecraft on the Moon several times previously.  Each attempt ended in failure.  The United States had the Surveyor project under development, but it had yet to see its first launch.  As was their custom, Jodrell Bank tracked the Luna 9 during its coast to the Moon, listening in on its telemetry signals and documenting the position and velocity of the probe throughout its flight.  On February 3, 1966, with an encounter speed of 6 meters/second (about 13 mph), the probe “crash-landed” on the lunar surface.  Signal transmission from the probe stopped abruptly.  The team at Jodrell Bank assumed that the mission was over, surmising that Luna 9 probably hit the Moon too hard or was designed as a crash lander.  Then to their astonishment, the probe began transmitting radio signals and the observatory recorded them, uncertain as to their meaning.

Lovell thought – suppose these signals were simply an ordinary telefax communication?  If these transmissions were pictures of the lunar surface, perhaps the signals the observatory recorded could be read by a commercial facsimile machine.  But Jodrell Bank Observatory had no such machine; the observatory was a scientific laboratory, which in those days displayed its received radio signals in the form of line graphs made by paper strip recorders.

Enter the power of the press!  The local office of the London Daily Express rushed a fax machine to the observatory where Lovell and his staff printed out the first picture of another planetary surface ever returned to Earth.  Because the staff of the observatory didn’t know anything about Luna 9’s encoding system design, they had to guess at the ratio of the horizontal to vertical dimensions of the image.  They guessed wrong.  The resulting image showed a jagged, rough peak-like surface, although apparently fine-grained. To both the chagrin and annoyance of the Soviet builders of Luna 9, surface images were released to the world press by the British observatory, leading to an amusing sequence of scientific “instant interpretation” that appeared in the press over the days that followed.

In the early days of lunar science, an intense debate raged over the geologic nature of the Moon.  Was it a cold, ancient body that had never undergone melting?  Chemist Harold Urey and Astronomer Thomas Gold thought so.  They postulated that the Moon was a giant, primitive chondrite meteorite, an unmodified piece of the early solar nebula that would tell us about the cold accretion of the planets.  Additionally, Gold was famous for his idea that the dark maria of the Moon were large “dustbowls” in which a heavy spacecraft would slowly sink like a body caught in quicksand on the Earth.

In contrast, many geologists and some astronomers thought otherwise – in their view, the Moon was a body shaped by internal melting, magmatic activity and volcanic eruptions.  These “hot moon” people saw evidence for volcanism in many lunar surface features, from the maria to craters.  Some, such as the founder of the field of planetary geology, Eugene Shoemaker, had a more nuanced viewpoint, ascribing both impact and volcanic origins to specific features, as appropriate.  Although the hard landing American Ranger spacecraft had transmitted high resolution video pictures before hitting the Moon, it did not survive the lunar impact and no one had seen a picture of the surface from a vehicle that landed softly enough to survive and long enough to send back a picture, until now.

A cascade of instant science followed the release of the Jodrell Bank images. Tommy Gold claimed that the pictures validated his dust bowl idea, even though it showed a fine-grained surface strewn with rocks (which Gold thought were clods of fine dust).  Gold also said that the Luna 9 capsule was slowly sinking into the surface (in accordance with his model, of course) and would soon sink out of sight.  Gerard Kuiper of the University of Arizona thought that the surface of the Moon was composed of bare, dust-free bedrock and so interpreted the new Luna 9 images thusly.  U.S. Geological Survey geologist Hal Masursky said that the image looked like the rough, clinkery surface of a jagged lava flow (a surface for which geologists give the Hawaiian name “aa”) and was clearly of volcanic origin.  An eager reporter pressed him:  this surface is volcanic – isn’t that where gold is sometimes found on Earth?  Hal distractedly nodded agreement, leading to the ludicrous headline that Luna 9 had found veins of gold on the Moon.

Alas, there was gold — scientific gold.  The distortion of the image caused by a wrong guess of the aspect ratio by the staff of Jodrell Bank soon was corrected when the Soviets released their own version of the image.  The lunar surface consists of fine-grained dust, smooth and undulating (because of the presence of a myriad of small surface craters), with the occasional rock lying about — no dust bowls, no bare bedrock, no “quicksand,” no aa lava flows, and no veins of gold.  The disappointment of the press was palpable.

The tendency of scientists to see confirmation of their own predispositions in the new data is striking.  We all are human, possessing the natural inclination to interpret new data in a way most favorable to our own long-held beliefs.  In this instance, a simple and excusable error in the reconstruction of the surface image led to abundant egg on the faces of most of the world’s experts on lunar science.  Instant science is often wrong at worst or incomplete at best.

Originally published at his Smithsonian Air & Space blog The Once and Future Moon, Dr. Spudis is a senior staff scientist at the Lunar and Planetary Institute. The opinions expressed are those of the author and are better informed than average.

Related Post:
"Boy that sure looks like Luna 9!" (December 3, 2011)

LROC: Debris Channels

Granular materials once flowed down the crater wall of Alpetragius B and formed these striking patterns. LROC Narrow Angle Camera (NAC) observation M170606933L, LRO  orbit 10276, September 14, 2011; angle of incidence 17.54° at half-meter resolution from an altitude of 45.12 kilometers. See the full size LROC Featured Image 600 meter field of view HERE [NASA/GSFC/Arizona State University].
Lillian Ostrach
LROC News System

Crater modification is a topic of interest to lunar scientists because most of the impact craters on Earth are heavily degraded. Meteor Crater is the best-preserved and youngest impact crater studied on Earth, and fieldwork spanning as far back as the 1800s has greatly improved the understanding of crater formation and modification. By comparing geologic features on the Moon to those that are well-studied on Earth, scientists can begin to understand the complexity of geologic processes that constantly change the lunar surface.

Granular debris flows are the result of material moving downhill due to gravity. The flows often contain fine-grained material, forming a smooth, fluid-like texture, and may be mistaken for impact melt flows. Today's Featured Image highlights the complex and diverse nature of debris flows that represent erosive events that are likely occurring on the Moon today. Located on the eastern wall of Alpetragius B crater (~10 km diameter) in Mare Nubium, this debris flow (15.119°S, 353.253°E) is composed of multiple channels and different sized materials.

Elsewhere, on the north side of the first big bend past the "Cobra's Head" (25.45°N, 49.46°W), widest part of Vallis Schroteri on Aristarchus Plateau, a 1600 meter-long debris channel fans out on the valley floor after a steep 800 meter fall. (Watch your step!). LROC NAC observation M170884438R, orbit 10137, September 17, 2011; angle of incidence 27.86° at 49 centimeters per pixel resolution, from 43 kilometers [NASA/GSFC/Arizona State University].
Rubbly, higher reflectance material (opening image, to the right) appears to be surrounding and somewhat interspersed with a lower reflectance, finer-grained material composing the flow. Where the flow is composed of separate channels (opening image, to the left), the fine-grained material is bordered by the higher-reflectance material.

LROC WAC monochrome mosaic centered on Alpetragius B (15.137°S, 353.128°E) in Mare Nubium. Location of opening image noted by asterisk [NASA/GSFC/Arizona State University].
Perhaps the finer-grained debris carved through an older flow composed of the higher reflectance material. This hypothesis may be supported by observations within the image. For example, the rubbly material is visible elsewhere on the crater wall where the finer-grained material is not. The rubbly, higher reflectance material extends beyond the fine-grained, channeled flow (middle right and middle left). Additionally, the fine-grained flow channels cross-cut one another multiple times, but the higher reflectance material does not border those channels. However, additional observations should be made to make sure that the flow in the opening image is representative of the debris flow populations in Alpetragius B and not a special case.

What evidence can you find that to support the hypothesis about debris flow formation in Alpetragius B? Grab your notebooks and take a look at the full LROC NAC image, HERE.

Related Posts:

Tuesday, August 7, 2012

LROC: Mounded Floor

Blocky crater (~500 m diameter) with a central mound, located in Mare Frigoris. LROC Narrow Angle Camera (NAC) observation M170605553R, LRO orbit 10276, September 14, 2011; angle of incidence 60.61° from 47.08 kilometers, resolution 0.51 meters - field of view width 800 meters. See the spectacular full-size LROC Featured Image (1600 px) HERE [NASA/GSFC/Arizona State University].
Lillian Ostrach
LROC News System

Blocky craters in the mare are frequently imaged by the LROC NACs. Today's Featured Image is a ~500 m diameter crater in Mare Frigoris with blocks and a central floor mound. The typical depth of excavation for simple craters is about one tenth of the crater diameter, so the crater above excavated mare material from up to 50 meters below the surface. 

The excavated material is probably a combination of regolith breccias formed during the impact and ejected fragments of bedrock. Additionally, the ejecta closest to a crater's rim is usually from the deepest part of the crater, so the blocks near the rim are probably recently exposed mare basalt rocks excavated during impact.

LROC monochrome (566nm) Wide Angle Camera image of the Mare Frigoris basalts, centered on the crater with a mounded floor (58.96°N, 8.1°W). Asterisk notes location of opening image [NASA/GSFC/Arizona State University].
The interior morphology of craters, whether they are bowl-shaped, have a central mound, or have benches, is dependent on impact mechanics and target properties. In the 1960s, laboratory cratering experiments successfully created crater landforms similar to those observed in Lunar Orbiter images. In several key papers1, Drs. Quaide and Oberbeck studied the effects of impacting conditions such as gravity, impact velocity, and the target surface with respect to final crater shape.

These scientific studies determined that the type of target material was a substantial factor in controlling interior crater morphology, and that different crater morphologies are formed based on the thicknesses of surface regolith atop stronger rock layers. The central mound observed in today's Featured Image can thus be explained as a result of an impact into a cohesive rock substrate overlain by a relatively thin layer of regolith. What do you think would happen to the interior morphology if the crater was bigger, or smaller?

Can you find additional craters with central mounds in the full LROC NAC frame?

1In the 1960s, impact mechanics experiments greatly furthered scientists' understanding of the impact process. Many publications detail these studies, but three references are particularly noteworthy: Gault, D. E., W. L. Quaide, and V. R. Oberbeck, Impact cratering mechanics and structures, Shock Metamorphism of Natural Materials, 87-99, 1968. Oberbeck, V. R., and W. L. Quaide, Estimated thickness of a fragmental surface layer of Oceanus Procellarum, J. Geophys. Res., 72, 4697-4704, 1967. Quaide, V. R., and V. R. Oberbeck, Thickness determinations of the lunar surface layer from lunar impact craters, J. Geophys. Res., 73, 5247-5270, 1968.

Related Posts:
Another, relatively fresh crater with a mounded floor, with twin pools of melt, (43.16°S, 68.98°W) near Vallis Inghirami, in the southwest near side, has been subject to more than one LROC NAC observation. This one, above, and below, at full resolution, is scaled from LROC NAC frame M175739695, orbit 11033, November 12, 2011. The incidence angle is 59.61° at 43 centimeters per pixel resolution, from 31.26 km [NASA/GSFC/Arizona State University].

Thursday, August 2, 2012

LROC: Sinuous Ridges on the Slope

Triple junctions of wrinkle ridges at the western edge of Bolyai crater floor. Image field of view is 1270 meters, LROC Narrow Angle Camera (NAC) observation M134368363L, LRO orbit 4935, July 21, 2010; incidence angle 72.2° at 1.27 meters resolution from 61.04 kilometers. Sunlight is from the west. View the larger (~80%) original LROC Featured Image HERE [NASA/GSFC/Arizona State University].
Hiroyuki Sato
LROC News System

Today's Featured Image involves sinuous ridges observed at the western edge of the mare basalt deposit on the floor of Bolyai crater. Bolyai is a ~100 km diameter crater located at 33.85°S, 126.12°E, about 400 km south of Tsiolkovskiy crater. The northern part of the crater floor is filled by a mare basalt deposit (see WAC context image at the bottom of this post). Notice that the sunlight is from the left side of the image, thus the circular features (craters) are negative relief and sinuous line-features are positive relief.

The ridges show bifurcations at the middle of the image, and two ridge branches extending toward the northeast and southeast of this image gradually become less apparent. The southwestern branch strongly meanders and eventually disappears as well. On the other hand, the northwestern branch extends on the crater slopes all the way along the western boundary of the mare deposit (see the NAC context image below), about 80 to 300 m away from this "shoreline". How did all these ridge systems form? Could they really be "splash marks" like in Tuesday's post, or are they something else?

Western edge of mare basalt deposits, traced by wrinkle ridges on the slopes of Bolyai crater wall. A section of the width of LROC NAC frame M134368363L is layered on the Google Earth lunar digital terrain model. Section field of view is approximately 2.4 km across, and the area in the Featured Image is outlined by the white box [NASA/GSFC/JAXA/USGS/ASU].
In many cases, splash marks include boulders that were deposited at the "wave front" of the melt, which is not the case in today's image. The wrinkle ridges, a compressional deformation feature caused by thrust faults, can crosscut each other, which would explain the bifurcation of the ridges in the top image. But then, did the whole western part of the lava pond slip, forming the surrounding wrinkle ridges? Obviously, a series of complicated geologic events happened in this particular mare deposit within Bolyai.

Northern part of Bolyai crater, once again in Google Moon, and as the scene might be viewed from 47 km over a point southeast of the area of interest. LROC Wide Angle Camera (WAC) monochrome (604nm) mosaic stitched from observations gathered during 9 sequential orbital opportunities averaging 46.8 km, and at 62 meters resolution, November 25, 2011. The locations of the full NAC frame M134368363L is outlined by the blue rectangle and the yellow arrow marks the approximate location of the field of view highlighted in the LROC Featured Image released August 2, 2012 [NASA/GSFC/Arizona State University].

Explore this set of sinuous ridges full LROC NAC frame for yourself, HERE.

Related Posts:
Constellation Region of Interest at Mare Tranquillitatis
Wrinkle ridge in Oceanus Procellarum
Stress and pull
Tectonics in Mare Frigoris
Bulging Wrinkle

Apollo 15 departs Hadley Rille Delta - 41 years ago


August 3, 1971 - 1:11 pm (EDT-US): Hadley Delta, Palus Putridanis, Earth's Moon. Lift off of Apollo 15 lunar module ascent stage, with Dave Scott and Jim Irwin on-board, as captured by remote-operated live color television camera on Apollo's first lunar rover.


From automated DAC camera - on-board lunar module Falcon: From ascent stage ignition through pitch-forward and an excellent - though brief - view of the descent stage/launch pad left behind and below. This footage shows the range track west, over Hadley Delta and Hadley Rille, through a slight roll maneuver allowing a longer view of Hadley Rille north of the landing site and points west over the Palus Putridanis formation on the southeastern frontier of Mare Imbrium.

 [NASA/GSFC/Arizona State University].
The animation above views the Apollo 15 landing site through shifting shadows of a lunar day, courtesy of the LROC Featured Sites index which premiered ;ast month. After the dust settled, almost immediately following the departure of Scott and Irwin expedition 41 years ago, the Sun has passed overhead 548 times, and very little appears to have changed.

A Lasting Legacy: Short of a large erasing impact or interference by future visitors, the relentless bombardment of micro-meteorites will eventually "garden" the top three centimeters or so of regolith, finally erasing all traces of the rover tracks and footprints in about 2 million years. After that, it's anyone's guess how long it might take to pummel away the artifacts of Apollo 15.

Tranquility Base at high-resolution before Apollo 11

On Monday, August 1 the Lunar Orbiter Image Restoration Project (LOIRP) released another 'newly retrieved' medium resolution frame 2085 M, originally photographed by Lunar Orbiter II on November 20, 1966, from its vantage point 51.4 kilometers over the southwest Mare Tranquillitatis (0.8°N, 23.7°E).
The Lunar Orbiter Image Restoration Project (LOIRP) has released an image from 1966, showing 'Tranquility Base' before the arrival of Apollo 11, newly-retrieved from once-discarded Lunar Orbiter telemetry tapes using restored and equipment built from scratch to read them.

It was early mid-morning on the Sea of Tranquility and the eventual landing site of Apollo 11 (small blue arrow in the thumbnail image, above) only 32 months later, when Lunar Orbiter II photographed the historic location. 

A very large version of the image, newly retrieved from the original taped telemetry returned from the JPL orbiter, at a digital resolution of 16500 x 18564 pixels (598.3 Mb) is housed at the NASA Lunar Science Institute, HERE. Original reproductions of second-generation photographs, along with image references, are available at the Lunar and Planetary Science Institute, HERE.

A large 1650 x 1856 version is available from the Moonviews.com website, HERE. Detailed full-resolution views of the landing site of Apollo 11 before and after July 20, 1969 are visible in the images below.

A rough outline of the field of view captured by Lunar Orbiter II traced out on the global LROC Narrow and Wide Angle Camera mosaic on the LROC QuickMap web-application, at a resolution of 64 meters. The Apollo 11 landing site is indicated by the red cross [NASA/GSFC/Arizona State University].
The Apollo 11 descent stage (blue arrow) is clearly visible when the LROC QuickMap is reset to 2 meters resolution, a close match to the full resolution close-up on the same area photographed by Lunar Orbiter II a year and eight months before the landing, below
A quick examination of the 16500 x 18564, 600 Mb full resolution version of LO-II-085 shows the landing site and many details of the vicinity familiar to those acquainted with mission details, before the arrival of Apollo 11. Excellent detail for this media, even without teasing out more detail using present-day software [NASA/JPL/LOIRP/NLSI].

Wednesday, August 1, 2012

LROC: Impacts on the Impact Melts

Impact melt surface ejected from Necho crater. Field of view width is 620 meters, LROC Narrow Angle Camera (NAC) observation M134374642L, LRO orbit 4936, July 21, 2010; Sunlight from the west, angle of incidence 68.85° at 0.62 meters resolution from 59.98 km. View the larger original LROC Featured Image HERE [NASA/GSFC/Arizona State University].
Hiroyuki Sato
LROC News System

Today's Featured Image looks vaguely like a microscope picture of onion cells (complete with a nucleus and cell walls), but in reality this is an impact melt deposit that extends out of Necho crater (5.25°S, 123.24°E; see whole view of this melt sheet HERE).

In between the network shaped cracks (notice that the sunlight is from left of the image, thus lineations are negative relief), multiple strangely-shaped craters with a central dent surrounded by a flat moat about 15 to 40 m in diameter are observed. They resemble bench craters (e.g. Fresh Bench Crater in Oceanus Procellarum, Bench Crater in Plato), except that they are not quite circular in shape and no radial ejecta is visible. The relatively bigger one near the image center has deeper dent and a petal shaped system of exterior deposits.

Full size field of view in the LROC Featured Image in context with the larger NAC frame M134374642L at roughly 4 meters per pixel resolution, shows some of the complexity of the impact melt on the east flank of Necho [NASA/GSFC/Arizona State University],
Necho crater and its eastern side, dominated by its ejecta deposits,  in viewed on the digital terrain model available in the Google Earth application, overlaid with the 604nm monochrome data from LROC Wide Angle Camera observation M165041995C, LRO orbit 9456, July 11, 2011; resolution 86.15 meters from 61.3 km. The locations of full NAC frame (blue box) and the field of view, highlighted in the LROC Featured Image (yellow arrow, 4.79°S, 124.125°E) are indicated [NASA/GSFC/Arizona State University].
These strangely-shaped craters are probably self-secondary craters, formed after the emplacement of the impact melt deposit but before the complete solidification of the molten rocks. The physical properties of unsolidified target might have resulted in these distinctly-shaped craters.

Explore more strangely-shaped craters on Necho's impact melts in the full LROC NAC image, HERE.

Related Posts:
Splash Mark at Necho crater (July 31, 2012)
Fresh Bench Crater in Oceanus Procellarum (December 23, 2011)
Bench Crater in Plato (November 9, 2011)
Impact melt at Necho crater (September 1, 2010)
A molten flood (July 28, 2010)
Necho Crater (August 22, 2009)

Tuesday, July 31, 2012

LROC: "Splash Mark" at Necho crater

Meandering line of boulders at the bottom of Necho crater. Image width is 690 m, LROC Narrow Angle Camera (NAC) observation M167390131L, LRO orbit 9802, August 7, 2011; incidence angle 47.08° at 0.69 meters resolution, from 60.11 km. Sunlight is from west (left side) [NASA/GSFC/Arizona State University]
Hiroyuki Sato
LROC News System

Today's Featured Image highlights the southern edge of an impact melt pond, located on the floor of Necho crater. Necho is a relatively young, Copernican-aged crater (meaning, it formed between ~1.1 billion years ago and the present) with a diameter of 30 km, located on the farside of the Moon (5.25°S, 123.24°E).

As seen in the WAC context image below, the crater floor is filled by impact melts. The meandering line of boulders in the opening image was found near the bottom of a north to northeast facing slope. There is no clear relief or texture difference on the surface except this boulder line. How was it formed?

Necho crater as viewed on the digital terrain model available in the Google Earth application, overlaid with the 604nm monochrome data from LROC Wide Angle Camera observation M165041995C, LRO orbit 9456, July 11, 2011; resolution 86.15 meters from 61.3 km. The locations of full NAC frame (blue box) and the field of view highlighted in the LROC Featured Image (yellow arrow) are indicated [NASA/GSFC/Arizona State University].
Probably this line of boulders was formed as a splash mark or wave front coming from the melt pond, driven by secondary impacts or debris dumped into the melt pond. In fact, impact melt flows frequently retain similar boulder lines along the edge of each flow unit (see Scale-like Impact Melts, A molten flood). Also, discontinuous boulder marks at the upper part of this image extend downslope, near the relatively level melt pond area, which might be a side of the splash flow.

Explore the full NAC view of Necho's impact melt pond HERE.

Related Posts:
Necho Crater (August 22, 2009)
A molten flood (July 28, 2010)
Necho's terraces (August 31, 2010)
Impact melt at Necho crater (September 1, 2010)
The jumbled floor of Necho crater (September 2, 2010)
Impact melt in Anaxagoras crater (May 31, 2011)
LROC: Jackson Waves, (August 10, 2011)
Scalelike Impact Melts (April 19, 2012)

'Man's First Wheels on the Moon,' at 41 years

Loading up the first of the Apollo lunar rovers, lunar module pilot Jim Irwin paused to memorialize the placard commemorating 'Man's first wheels on the Moon, Delivered by Falcon, July 30, 1971. Forty-one years later, the relatively low mileage electric car still sits on the plain north of Hadley Rille. Strictly speaking, the Lunokhod teleoperated rover on the opposite side of Mare Iridium were the first "wheels," on the Moon. In American parlance, however, this first of the three Apollo J mission Lunar Electric Rovers, operated by men behind the 'wheel,' were correctly designated the first "wheels" on the Moon AS15-88-11862 [NASA/JSC/ALSJ].
J. Terry White
President and CEO
White Eagle Aerospace, LLC
American Aerospace blog, Seattle Post Intelligencer

Forty-one years ago today, Apollo 15 landed in the Hadley-Appennine region of the Moon. The fourth manned lunar landing, Apollo 15 was one of the most scientifically successful and geologically diverse of the Apollo Lunar Landing Program.

The Apollo 15 Lunar Module Falcon, with Dave Scott and Jim Irwin onboard, landed at 22:16:29 UTC in the Hadley-Appennine region of the Moon on Friday, 30 July 1971.  High overhead, Al Worden orbited the Moon alone in the Command Module (CM) Endeavor.

Read this mission summary, HERE.
And explore the full mission record, videos and pictures 
at the Apollo 15 Lunar Surface Journal, HERE.

Apollo 15 Related Posts: