Lobate Scarp or Fluidized Ejecta?

A double merges into a single escarpment, part of a dramatic scene near 32.8°N, 215.08°E on the floor of an unnamed crater superimposed on the larger farside highland crater Blazhko D. LROC Narrow Angle Camera (NAC) observation M105463860R, LRO orbit 694, August 21, 2009; field of view around 1500 meters at an incidence angle of 51.02° from an early Commissioning Mission altitude of 166.2 km. See the full size original LROC Featured Image HERE [NASA/GSFC/Arizona State University].

James Ashley
LROC News System

Is this meandering escarpment an example of 1) a lobate scarp, or 2) imbricated deceleration lobes? Lobate scarps represent portions of the lunar crust that thrust-faulted, with one portion riding up and over the other in a process that is suggestive of crustal shrinking. Imbricated deceleration lobes result from fluidized impact ejecta deposits, with some deposits riding up and over others in a similar-looking way. Fluidization in this sense should not be confused with liquid or water - these materials are totally dry!

The cause of this type of fluidized flow remains somewhat unknown, but may involve acoustic energy within the moving mass of debris. Some of this energy may be supplied by the surface beneath the debris flow as secondary impacts and tectonic readjustments keep it vibrating following the large impact that initiated the flow. Try pouring some sand on a slanted board while you drum on the board with your fingers. You will see that the drumming removes most of the friction and allows the sand to flow freely. These type of flows often travel great distances before losing energy as they encounter slopes too steep to climb. On Earth we call them sturzstroms.

A complication in the case of today's Featured Image is the presence of scarps that are clearly related, but which oppose each other in their orientation (left side of frame).

Extensions of the scarp are visible far beyond the field of view of the Featured Image (white square) in much larger 5500 meter-wide segment from LROC NAC frame M105463860R [NASA/GSFC/Arizona State University].

The presence of this feature within the deposits of a highland crater floor might argue that fluidized ejecta are responsible because these debris flows often collect (some even appear to 'pool') within the low-lying crater floors. The material could be seen as so fluid that even after portions of the material have climbed the crater wall and stalled, other portions are able to slide backward to create the secondary 'reverse' escarpment in the Featured Image. Similar features within fault escarpments are not unheard of, however, and are referred to as splay faults. Thus the discussion remains an open one...

From the LROC QuickMap a contextual image showing both the left and right frames of LROC NAC observation M105463860 juxtaposed surrounding the field of view (white square) in the 5500 meter-wide image immediately above  [NASA/GSFC/Arizona State University].

LROC Wide Angle Camera (WAC) 100 meter resolution context image superimposed upon the LOLA Digital Elevation Model from the NASA ILIADS lunar mapper program. The elevation in meters above the global mean is shown at selected points around the spotlighted area [NASA/GSFC/Arizona State University],

Additional indications of fluidized ejecta are located throughout the surrounding region in the above context image. However, although a great many highland craters are present within this region of the Moon, none stand out as being the unambiguous source of these deposits. Knowing the true mode of origin for features like these is basic to the goals of planetary science. A properly equipped team of astronauts conducting seismic measurements is probably required to make a definitive determination. Are there any additional clues visible in the full NAC image that might help solve the mystery? Examples of lobate scarps can be found in Schrödinger, and Xenophanes craters. Examples of fluidized ejecta include the Lavish Lobes of Necho R and King Crater Ejecta Deposits.

LROC: Bench Crater in Plato

A small impact feature in the lava-filled crater Plato (51.6°N, 350.7°E) exhibits an interesting morphology. LROC Narrow Angle Camera (NAC) observation M137610258L, LRO Orbit 5413, August 28, 2010; incidence angle 60.43° field of view 550 meters from 48.4 km attitude. View the full size LROC Featured Image HERE [NASA/GSFC/Arizona State University].

James Ashley
LROC News System

Impact craters of the size shown above are often bowl-shaped, but can also present flat bottoms and concentric or 'bench' features like those seen here.

This small (~140 m diameter) crater is characterized by a low-relief rim, shallow and hummocky floor containing a small central crater, and a large population of associated blocks or boulders. Blocky and irregular craters are often the result of low-velocity secondary impacts, but can result from high velocity as well. The circularity of this crater suggests that it is the result of a high-velocity, primary impact.

LROC Wide Angle Camera 100m monochrome mosaic affixed to to LOLA elevation data in NASA's ILIADS lunar mapper program  are used to create an oblique view centered on the small crater, from a point at 5000 meters elevation and 18 km south. The elevation of the crater (yellow circle) and a few selected points are used to illustrate the stark slope of the 2 kilometer high inner walls of Plato.

The view from directly overhead: LROC WAC observation M119931570M, LRO Orbit 2808, February 4, 2010 very near to its full 54.08 meter per pixel resolution from 38.6 km altitude; incidence angle 66.15° The yellow arrow marks the location of the small bench crater, barely visible at the limit of unprocessed visibility [NASA/GSFC/Arizona State University].

Plato in a field of view assembled from four sequential LROC WAC orbital observation opportunities, February 4, 2010. Even an image that seems to take all of Plato in fails to allow a full appreciation of the topographic impact, so to speak, of the crater on its surroundings, part of the outer rim of the Imbrium impact event. Three sinuous channels radiate from Plato, perhaps out from under its rim. One of these is a Constellation Region of Interest [NASA/GSFC/Arizona State University].

Plato from Zottengem, Belgium, February 17, 2008 (C9.25@F/20, DMK31AF@30fps) An example of the increasingly spectacular work by talented observers of the Moon spotlighted on Charles Wood's justifiably popular website Lunar Picture of the Day [Bart Declercq].

Experiments were conducted in the late 1960's using a high-speed gun to fire projectiles at targets in an attempt to understand the process of small crater formation. Loose sand and epoxy resin-bonded sand was used to simulate lunar soil (regolith) over a hard bedrock substrate. These experiments determined that different types of small crater morphologies result from different thicknesses of lunar soil. The bench crater morphology shown in today's Featured Image forms when the regolith is thin with respect to the crater's final diameter.

Our featured impact had enough energy to penetrate the lunar regolith layer to the hard basaltic bedrock beneath. But because the lunar soil is unconsolidated, this energy was more effective in displacing the soil than the bedrock. Hence, we see a wide impact feature with a shallow bottom instead of a bowl. The substrate does not have to be bedrock to produce a bench crater, but there must be a contrast in target strength. The clear presence of boulders in the case of today's featured crater does, however, indicate that bedrock fragmentation was involved in its production.

Are there any similar craters visible in the full NAC image?

See other examples of interesting small craters here, here, and here.

LROC: "The Chicken or the Egg"

Building-sized boulders partially coated in impact melt on the southeast rim of Klute W (38.0°N, 216.7°E), from LROC Narrow Angle Camera (NAC) frame M140840176R, LRO Orbit 5889, October 4, 2010, incidence angle is 39.6° and a field of view width of 540 meters from 63.03 km. View the full size LROC Featured Image HERE [NASA/GSFC/Arizona State University].

James Ashley
LROC News System

Which arrived first, the impact melt or the boulders in this image? In other words, did these boulders arrive after melt had pooled, displacing the melt while still molten; or were they there in advance of the melt, which flowed around and partially over their southwest flanks? 

While there are no obvious signs of a 'splash' in this melt that might indicate the late arrival of the blocks, this question still seems like a bit of a puzzle at this image scale. 

Zooming out a little provides the information required to answer the timing question ...

This wider context image shows the melt as part of a shallow flow, and not a pool; image field of view is 2.7 km, white square shows area within the Featured Image. See the full size context image HERE [NASA/GSFC/Arizona State University].

In the above image, we can see how the melt flowed down this slope and around the boulders, which just happened to be in its path. The flow occurs on the portion of the Klute W crater wall adjacent to a neighboring crater, and along a portion of the rim where extensive mass wasting and other complex adjustments have occurred following the Klute W impact event.

A high degree of granularity is compromised when viewing the contact zone between Klute W and wider, much older Klute (lower right) using the 250 meter resolution LROC WAC Digital Terrain Model (DTM) (available through the LROC QuickMap) at 64 meter per pixel close-up. The smaller area in the Featured Image is just northeast of the 4855 meter elevation mark. Still, the range of color contrast hints at Klute W superimposition on the northwest rim of Klute [NASA/GSFC/Arizona State University].

LROC Wide Angle Camera (WAC) mosaic situated on the USGS/JAXA digital elevation model (DEM) installed in the Google Earth application. The blur rectangle shows the general area within LROC NAC frame M140840176R. Mosaic of five sequential observation opportunities August 10-11, 2010, LRO orbits 5192-5196; average incidence angle 61.5° from 62 km [NASA/GSFC/Arizona State University].

LROC WAC monochrome mosaic of Klute W and its neighboring 100 kilometer-wide environment. Red square indicates Featured Image location . View the full size LROC context image HERE [NASA/GSFC/Arizona State University].

The full NAC image shows abundant additional features of high geologic interest. Other examples of lunar impact melt occurrence and behavior can be found here and here.

Related posts:

Impact melt on Klute W wall
Post-impact modification of Klute W

TSR: Fear of a Chinese Moon

Robert Bigelow, speaking at the ISPCS conference in New Mexico this month, claimed that China is on a path towards taking control of the Moon within 15 years [ISPCS].

Jeff Foust

The Space Review

Robert Bigelow is best known in space circles as the founder of Bigelow Aerospace, the company he created over a decade ago to develop commercial space habitats using expandable (or inflatable) technology licensed from NASA. The Las Vegas-based company has successfully launched two prototype modules, Genesis 1 and 2, to demonstrate the technology and has plans for larger modules and commercial space stations for companies and so-called “sovereign clients”, nations without their own indigenous space programs.

Bigelow’s plans originally generated considerable skepticism in the broader space community. However, as the company won success with its Genesis missions and found interest in its plans from potential customers and even NASA—which sees the demand generated by Bigelow’s commercial habitats as a key part of the broader business case for the agency’s commercial crew plans—Bigelow has gained considerable credibility. Now, he’s using the platform he has as one of the nation’s leading space entrepreneurs to broadcast a warning about an unusual, even quixotic, threat to America’s space ambitions: that China will, in effect, seize the Moon.

Speaking at the International Symposium for Personal and Commercial Spaceflight (ISPCS) in Las Cruces, New Mexico, earlier this month, Bigelow spent very little time talking about his own company and its ambitions.

Instead, he spent most of his nearly 40-minute speech focusing on his belief that, within 15 years, China will notonly land people on the Moon, but will claim it as its own territory, locking out the United States and other nations.

Why would China do such a thing? Bigelow is convinced that China’s quest for prestige—to demonstrate that it is the most powerful country in the world—will inevitably drive the country to lay claim to the Moon. “China already has a grand national vision,” he said. “Their vision is that China wants to be indisputably number one in the world, measured any way you want to measure.”

That means, he said, not just simply repeating the past achievements of the US in space but moving beyond them. “Why not take the all-important syllogistic next step: ownership, ownership, ownership?” he suggested. Doing so, he said, would generate “global psychological impact” and considerable prestige for the Chinese people. “I think nothing else the Chinese could possibly do in the next 15 years would cause as great a benefit for China,” he said.

He argued that China, with its growing wealth and its historical “ability to maintain focus”, would be in a position to land humans on the Moon and start making claims between 2022 and 2026. “China has an ability to focus and galvanize its programs because of the centralization of the government” that can allow them to stay on that schedule, he told reporters after his ISPCS talk.

One obvious obstacle is the Outer Space Treaty, of which China is a party, which prohibits countries from making territorial claims to the Moon or other celestial bodies. Bigelow suggested, though, that China could work to amend the treaty through the support of countries in Africa and Latin America where China is making major investments. Alternatively, he said, China could simply decide to withdraw from the treaty. Public opinion, he said, won’t be factor. “There isn’t going to be World War Three over this,” he said. “There isn’t going to be a single shot fired.”

Read the full article at The Space Review, HERE.

Cernan says China will be first back to the Moon

Apollo 17 commander Gene Cernan

Peter Rakobowchuk
The Canadian Press

Ottawa - Eugene Cernan, the last man to walk on the moon almost 40 years ago, is worried China will beat other nations back to the shiny orb.

"There's no question in my mind at all that they are going to develop the capability to go to the moon and probably establish colonies there to take advantage of some of the resources that are on the moon," he said on Wednesday.

China moved one step closer to setting up its own space station with the successful docking of two unmanned spacecraft above the Earth which was announced Thursday morning.

Cernan spent more than 70 hours on the lunar surface in December 1972 along with fellow U.S. astronaut Harrison Schmitt during the Apollo 17 mission.

He said China is "eight or ten years away" from landing on the moon and when they get there they are going to literally almost own it because no other countries have any plans to go there.

"The Chinese have a long-term plan that's going to leave the rest of us behind quite frankly and I'm worried about it," he said in an interview with The Canadian Press.

Cernan said if China assumes a position of leadership in space, "it's going to have significant negative effects on western civilization, particularly the United States — for many years to come."

The 77-year-old former astronaut made the comments at the First Aerospace Summit where he was also the keynote speaker.

Read the full story HERE.

EMCORE panels picked for LADEE

Albuquerque – EMCORE Corporation, a leading provider of compound semiconductor-based components and subsystems for the fiber optic and solar power markets, announced October 31 it's been awarded a contract by ASRC Research and Technology Solutions (ARTS) in Greenbelt, MD for design, manufacture and delivery of solar panels for NASA Ames Lunar Atmosphere and Dust Environment Explorer (LADEE) mission in 2013.

LADEE is a robotic mission designed to orbit the Moon. Its main objective is to study and characterize the lunar atmosphere, including fine dust particles suspended above the lunar surface. The spacecraft is currently scheduled to be launched in early 2013 aboard a Minotaur V vehicle from Wallops Island.

A total of 32 solar panels will be built for LADEE at EMCORE’s state-of–the-art manufacturing facilities located in Albuquerque, New Mexico.

Hadley Rille and the Mountains of the Moon

NASA Lunar Reconnaissance Orbiter (LRO) rolled to capture a dramatic oblique view of the Apollo 15 landing site 26.1°N, 0.25°E on the plains of Hadley Rille Delta. Hadley Rille, a great chasm in the lunar surface, carves through the center of this scene. Explore the full size LROC image HERE. LROC Narrow Angle Camera (NAC) observation M165842369, orbit 9574, July 20, 2011 [NASA/GSFC/Arizona State University].

Samuel Lawrence
LROC News System

On 20 July 2011 (coincidentally, the 42nd anniversary of the first steps humans took on another world) the NASA Lunar Reconnaissance Orbiter was commanded to roll to the east, allowing the Lunar Reconnaissance Orbiter Camera to obliquely observe Hadley rille and the Apollo 15 landing site. One of humanity's greatest voyages of exploration, the adventures of mission commander David Scott, lunar module pilot James Irwin, and command module pilot Al Worden transformed our understanding of the Moon and the Solar System. The shadow of the descent stage of the Lunar Module Falcon is visible, as is that of NASA's first lunar roving vehicle. Additionally, the sampling stations explored by the Apollo 15 astronauts are easy to pick out.

Full scope of the LROC NAC oblique frames detailed HERE. Hadley Rille is about 1.2 km wide. The whole scene is 28 kilometers from left-to-right [NASA/GSFC/Arizona State University].

Apollo 15 was the first of three long-duration “J-missions”; more would have flown had the Apollo program not been brought to a premature conclusion in 1972 after the Apollo 17 mission. The J-missions featured heavily instrumented command and service modules, improved spacesuits to promote crew agility, upgraded lunar landing vehicles, and the electric Lunar Roving Vehicles (or LRVs) to expand the crew's range on the surface. Prior to the mission, the Apollo 15 crew received extensive geoscience training, which (along with the increasingly capable hardware) resulted in an extraordinary bounty of scientific results. Apollo 15 was also the only lunar mission where all crewmembers were graduates of the University of Michigan and United States Air Force officers (the lunar module, Falcon, was named after the mascot of the United States Air Force Academy, and the Apollo 15 command module Endeavour is now on permanent display at the National Museum of the U. S. Air Force in Dayton, OH).

LROC NAC mosaic from M170538271, sampled at 2 meter pixel scale (from the original 0.5 m) showing area where lunar sample 15555, "Great Scott," was collected (Station 9A) west of the Apollo 15 landing site. View the larger original 2 meter image prepared for this essay HERE [NASA/GSFC/Arizona State University].

Astronauts Scott and Irwin spent almost three days exploring the Hadley-Apennine valley, traversed over 28 kilometers (17 miles) using the first lunar rover, and collected over 77 kilograms (170 pounds) of priceless lunar materials, including the famous “Genesis Rock”, a piece of the primordial lunar crust. While Scott and Irwin explored the surface, command module pilot Worden used the extensive instrument suite aboard the command module Endeavour to successfully complete a complex series of orbital observations. You can view digital scans of the original Apollo 15 flight films taken by Endeavour's Fairchild Mapping Camera at the Arizona State University Apollo Digital Image Archive! 

The geologically complex Apollo 15 site is a high priority target for future human lunar exploration, and consequently was one of the Constellation Regions of Interest that were a focus of LROC observations during the LRO Exploration Systems Mission Directorate mission (the 1st year of LRO operations). Thanks to the exploration of the Apollo 15 astronauts, we now have a well-defined set of scientific questions that can only be addressed through a future human sortie mission to the Hadley-Apennine region. In addition, recovering materials from the descent stage of Falcon would provide valuable information to present-day engineers about how materials survive on the lunar surface for long periods of time.

Edge of Hadley rille where lunar sample 15555 (Station 9A) was collected, August 2, 1971. The disturbed soil at 9A are the foot prints and LRV tracks left by Scott & Irwin, 40 years ago, testifying to the intensive study and sampling at this site. See the larger image prepared for this essay, from an observation not due for release until December, HERE [NASA/GSFC/Arizona State University].

On Saturday, November 5, as part of the School of Earth and Space Exploration's annual Earth and Space Exploration Day, Arizona State University unveiled a display featuring a piece of Apollo Lunar Sample (ALS) 15555, a mare basalt collected by Col. Scott about 12 meters from the rim of Hadley rille at Station 9A. This lunar rock is the largest and one of the most intensively studied samples collected by the Apollo 15 astronauts, and is predominantly composed of silicate minerals such as olivine, pyroxene, and plagioclase. The bulk composition of 15555 is thought to represent a primitive volcanic melt and has been used for experimental and theoretical studies related to the geologic origin of lunar basalts. Planetary scientists use information gleaned from such analyses to gain key insights into how terrestrial planets like the Moon and Earth form and evolve. Sample 15555 has also been used for critical tests designed to help perfect and calibrate methods of radiometric age dating employed by different laboratories around the world.

On their third EVA, before sampling 15555, Col. Scott took a picture of its location and immediately handed the camera to Jim Irwin, who then captured a series of shots for a standard panorama of Station 9a. The three legged gnomon was placed beside the sample so scientists could later determine its orientation of the rock on the surface [NASA, AS15-82-11164].

What is a mare basalt and what is its significance? The lunar mare basalts are very similar to terrestrial basalts. If you drove up to Sunset crater outside Flagstaff AZ, you can find basalt. If you go to Hawaii, Iceland, India, Ethiopoa and many other countries you can find basalt. The oceanic crust on the Earth is composed of basalt. If you visit Mars you will likely land on basalt or basalt derived sediments. If you land on Venus - same! The Dawn spacecraft is right now orbiting an asteroid, Vesta, that is composed of basalt. Basalt is common in the Solar System. The fascinating fact about basalts is that they represent a sample of the upper mantle. We can't get to the mantle directly, but nature provides us with samples of the deep interior (mantle) in the form of basalt. Volcanism is the delivery truck! Since the mantle makes up most of the mass of the Earth, Mars and the Moon we must have samples of the mantle to understand each body as a whole. You can think of 15555 as a piece of the Moon's interior, even though it was picked up on the surface.

Apollo Lunar Sample 15555 on display at the Lunar Reconnaissance Orbiter Camera Science Operations Center [E. Speyerer, Arizona State University].

A generous loan to Arizona State University from the NASA Lyndon B. Johnson Space Center, this 76 gram (2.7 ounces) piece of mare basalt will be displayed in the Lunar Reconnaissance Orbiter Camera Science Operations Center Visitor Gallery. This stunning and unique lunar sample display will enable visitors to view and learn about an amazing piece of our Moon, while just a few meters away, behind a glass partition, the LROC team is sending commands to LROC and receiving images in return that enable scientists and engineers to plan for future human and robotic exploration of the Moon.

We heartily encourage anyone interested in space exploration to come view this priceless American treasure and learn how lunar scientists around the world are pioneering your future in space. The work we do at LROC is tremendously exciting, but ultimately, it is the human passion for discovery that drives this enterprise.

Explore the complete NAC oblique image of the Hadley-Apennine valley!


Visit the LROC Science Operations Center

Read more about the Apollo 15 landing site
in previous LROC Team posts:

Layers Near Apollo 15 Landing Site (30 August 2011)
Retracing the Steps of Apollo 15: Constellation Program Region of Interest (16 April 2010)
LROC's First Look at the Apollo Landing Sites (17 July 2009)
Lunar Highs and Lows (22 July 2008)
The Mighty Apennine Mountain Range (30 September 2008)
Hadley-Apennine: the Apollo 15 Landing Site (14 November 2007)

Further Related Posts:

40th Anniversary of Apollo 15 celebrated at Kennedy Space Center
Al Worden award with Moon Rock
Kaguya captures Hadley Rille

Hadley Rille Valley of Palus Putredinis on the Imbrium side of the Apenninus mountain ridge, 1971 landing site of the Apollo 15 expedition. LROC Wide Angle Camera (WAC) mosaic from 7313 and 7314, January 24, 2011; resolution 53 meters, incidence angle 65.77° from 36.36 kilometers [NASA/GSFC/Arizona State University].

The replicators have arrived

"Slide show" comparing an illumination model of the lunar north pole region, made using a three-dimensional printer and LRO laser altimetry by Howard Fink of New York University, with standard representations of LOLA data and one LROC WAC mosaic [Howard Fink/NYU/NASA/GSFC/ASU].

Paul D. Spudis
The Once & Future Moon
Smithsonian Air & Space

Of all the wonders depicted in science fiction books and movies, one of the most intriguing is the machine that makes anything that you need or desire.  Merely enter a detailed plan, or push the button for items programmed into the machine – dials twirl, the machine hums and out pops what you requested.  Technology gives us Aladdin’s Lamp.  A handy device that will find many uses.

We’re not quite there yet but crude versions of such imagined machines already exist.  These machines are called “rapid prototype” generators or three-dimensional printers.  They take digitized information about the dimensions and shape of an object and use that data to control a fabricator that re-creates the object using a variety of different materials.  Typically, these machines use easy to mold plastics and epoxy resins but in principle, any material could be used to create virtually any object.

3-D printers contribute to the advancement our understanding of lunar morphology, as LRO fills long-neglected gaps in lunar morphology. Malapert Massif (85.9°S, 0.42°E). From an 80 meter resolution image of the South Pole region of the Moon built from a 20 meter original supplied by the LRO/LOLA science team [Howard Fink/NYU].

For comparison nearly the same area modeled by laser altimetry (LOLA) above, Malapert from the LROC Wide Angle Camera (WAC) RDR 100 meter Global Mosaic [NASA/GSFC/Arizona State University].

What’s the relevance of this technology to spaceflight and to the Moon?  One of the key objects of lunar return is to learn how to use the material and energy resources of the Moon to create new capabilities.  To date, we have focused our attention on simple raw materials like bulk regolith (soil) and the water found at the poles.  It makes sense to initially limit our resource utilization ambitions to simple materials that are both useful and relatively massive, which currently have those killer transportation costs when delivered from Earth.  Bulk regolith has many different uses, such as shielding (e.g., rocket exhaust blast berms) as well as raw material for simple surface structures.

However, once we are on the Moon and have met the basic necessities of life, we can begin to experiment with making and using more complex products.  In effect, the inhabitants of the Moon will begin to create more complicated parts and items from what they find around them, just outside their door.  The techniques of three-dimensional printing will allow us to discover what makes life off-planet easier and more productive.  We will experiment by using the local materials to maintain and repair equipment, build new structures, and finally begin off-planet manufacturing.

To illustrate the obliquity of the view angle and the problem posed in gathering information about the tantalizing but permanently shadowed regions of the Moon, Shackleton crater, with the Moon's South Pole on its rim (upper left) together with Malapert Massif on the horizon, seen with Earth as a back drop. HDTV still from Japan's Kaguya orbiter released November 2007 [JAXA/NHK/SELENE].

During the early stages of lunar habitation, material and equipment will be brought from Earth.  With continued use, particularly in the harsh lunar surface environment, breakdowns will occur.  Although initially we will use spare parts from Earth, for simple uncomplicated structures that are needed quickly, a three-dimensional printer can make substitute parts using local resource materials found near the outpost.  Most existing 3-D printers on Earth use plastics and related materials (which are complex carbon-based compounds, mostly derived from petroleum) but some processing has used concrete, which can be made on the Moon from sieved regolith and water.  In addition, we also know that regolith can be fused into ceramic using microwaves, so rapid prototyping activities on the Moon may eventually find that partially melting particulate matter into glass is another way to create useful objects.

The lunar surface is a good source of material and energy useful in creating a wide variety of objects.  I mentioned simple ceramics and aggregates, but additionally, a variety of metals (including iron, aluminum and titanium) are available on the Moon.  Silicon for making electronic components and solar cells is abundant on the Moon.  Designs for robotic rovers that literally fuse the in-place upper surface of the lunar regolith into electricity-producing solar cells have already been imagined and prototyped.  We can outsource solar energy jobs to the Moon!

These technical developments lead to mind-boggling possibilities.  Back in the 1940s, the mathematician John von Neumann imagined what he called “self-replicating automata,” small machines that could process information to reproduce themselves at exponential rates.  Interestingly, von Neumann himself thought of the idea of using such automata in space, where both energy and materials are (quite literally) unlimited.  A machine that contains the information and the ability to reproduce itself may ultimately be the tool humanity needs to “conquer” space.  Hordes of reproducing robots could prepare a planet for colonization as well as providing safe havens and habitats.

We can experiment on the Moon with self-replicating machines because it contains the necessary material and energy resources.  Of course, in the near-term, we will simply use this new technology to create spare parts and perhaps simple objects that we find serve our immediate and utilitarian needs.  But things like this have a habit of evolving far beyond their initial envisioned use, and often in directions that we do not expect; we are not smart enough to imagine what we don’t know.  The technology of three-dimensional printing will make the habitation of the Moon – our nearest neighbor in space – easier and more productive.  Even now, creative former NASA workers have found a way to make this technology pay off.  In the future, perhaps their talents could be applied to making the Moon a second home to humanity.

Originally published October 24, 2011 at his Smithsonian Air & Space blog The Once and Future Moon, Dr. Spudis is a Senior Staff Scientist at the Lunar and Planetary Institute in Houston. The opinions expressed are those of the author and are better informed than average.

LROC: A small crater's disappearing floor

Floor of unnamed crater inside the western rim of the Humboldt 'walled plain.' LROC Narrow Angle Camera (NAC) observation M113440414L, LRO Orbit 1851, November 21, 2009; resolution 51 cm per pixel, incidence angle 54° from 46.93 km. Field of view 296 meters across. View the wider full size LROC Featured Image HERE [NASA/GSFC/Arizona State University].

Hiroyuki Sato
LROC News System

Humboldt crater is a large (207 kilometers) floor-fractured crater on the eastern limb, as seen from the Earth, just before the 80° east meridian (in the Zone of Libration), about 760 km south of Mare Smythii. The edges of its fractured-floor are partially covered by dark mantle deposits, which are suspected to be pyroclastic in origin.

Today's Featured Image is the bottom of an unnamed 5.7 km crater near the western edge of the Humboldt crater floor (26.25°S, 78.41°E). The boomerang-shaped flat area in the center of this image is the original floor, surrounded by continuous slopes from the crater rim.

LROC Wide Angle Camera 100 m Global Mosaic fixed to an initial LOLA laser altimetry-based digital terrain model in a scene built up through the NASA ILIADS platform, where a variety of lunar probe data bases from multiple NASA centers are made available to the public.The asterisk marks the location of the field of view within the LROC Featured Image and the yellow rectangle indicates the LROC NAC image footprint from which it was taken [NASA/ILIADS].

The initial shape just after the impact event is generally thought to be a symmetric bowl-shape, with mass wasting gradually modifying the crater cavity. Especially for the small craters on the Moon, bowl-shaped cavities are transformed by this process into inverted cone shapes. This unnamed crater in Humboldt may be undergoing such a process now to become a complete cone shape at some point in the future. If so, we are fortunate to observe its original floor before complete burial obscures it from view.

A second, more recent LROC WAC monochrome (604 nm) mosaic of the western interior of the Humboldt plain, for comparison with the afternoon illumination further up it shows the unnamed crater in a field of view approximately 45 kilometers wide under early morning illumination. LROC WAC observations M161801162C, M161794365CE & M161787569CE in LRO orbits 8976-8978, June 4, 2011; average resolution 66.75 meters, incidence angle 70.8° from 47.45 kilometers [NASA/GSFC/Arizona State University].

LROC WAC monochrome mosaic around Humboldt, with a false-color overlay representing the LROC photography-based digital terrain model (DTM), at (default) 30% opacity and 250 meter resolution, as viewed through the LROC QuickMap web-based application. The unnamed crater and its surroundings are seen in the wider context of Greater Humboldt on the western edge of the larger crater floor, with its high walls and radial fractures. View the full size original LROC WAC context image HERE [NASA/GSFC/Arizona State University].

Explore the last portion of this unnamed crater floor in the full NAC frame yourself!

Related posts:
Craters on the Schrodinger pyroclastic cone
Melt and more melt
Small crater in Oceanus Procellarum

Mighty Eagle lander 100 foot flight at Redstone

Kim Newton
Marshall Space Flight Center

NASA will conduct a 100-foot robotic lander altitude test flight Friday, Nov. 4, to mature the technology needed to develop a new generation of small, smart, versatile robotic landers capable of achieving scientific and exploration goals on the surface of the moon, asteroids or other airless bodies.

The test will begin between 10:30 - 11 a.m. CDT and will air live on NASA Television's Education Channel and the agency's Website. The outdoor test will occur at the U.S. Army's Redstone Test Center on Redstone Arsenal in Huntsville, Ala., and is weather dependant.

The lander prototype will perform an autonomous hover test, flying up to 100 feet and then translate, or move sideways, to perform a controlled, safe landing 30 feet away from the launch pad. The lander, dubbed Mighty Eagle, is fueled by 90 percent pure hydrogen peroxide and receives its commands from an onboard computer that activates its onboard thrusters to carry it to a controlled landing using a pre-programmed flight profile. This series of tests demonstrate the test article’s capability to perform an autonomous descent and landing and are being used to checkout landing control algorithms for the next generation of lander missions.

Journalists can attend the test or participate in a media telecon 45 minutes after the altitude test flight. Telecon participants will include Greg Chavers, lead systems engineer for the Robotic Lander Development Project at NASA's Marshall Space Flight Center in Huntsville., and Julie Bassler, project manager for the Robotic Lander Development Project at Marshall. The project is managed by NASA's Science Mission Directorate in Washington.

To attend these events, reporters should contact Kim Newton, Marshall Public and Employee Communications Office at 256-544-0034 no later than 4 p.m. CDT Thursday, Nov. 3. Media representatives must report to the Redstone Visitor Center at Gate 9, Interstate 565 interchange at Rideout Road/Research Park Boulevard. Vehicles will be subjected to a security search at the gate. Journalists will need two photo identifications and proof of car insurance.

For NASA TV streaming video, downlink and scheduling information, visit: http://www.nasa.gov/ntv

The test also will be webcast live via Ustream at: http://www.ustream.tv/channel/nasa-msfc

LROC: Boulder rich crater on floor of Aitken

Full resolution (65 centimeter per pixel) view of the boulder-rich central zone in an unusually shaped small crater north of Aitken N, on the wide floor of farside landmark crater Aitken. LROC Narrow Angle Camera (NAC) M141132981R, LRO Orbit 5932, October 7, 2010. Field of view is 378 meters wide, incidence angle 17.79° from 63.6 km. From LROC Featured Image released November 2, 2011 [NASA/GSFC/Arizona State University].

Wider angle view of the unnamed diamond-shaped and boulder-rich crater on the floor of Aitken. See the full size LROC Featured Image HERE [NASA/GSFC/Arizona State University].

Hiroyuki Sato
LROC News System

This extremely boulder-rich, unnamed crater is located on the floor of Aitken crater (at the north rim of South Pole Aitken Basin); the diameter is about 480 meters. The floor of Aitken crater is thought to be resurfaced by post-impact lava flows, which corresponds to the low-reflectance smooth surface. The unnamed crater impacted with and excavated these putative lava flows long after the lava solidified.

The high-reflectance boulders of this crater are mostly distributed within the crater cavity, and very few are visible in its ejecta. The extent of this ejecta, traced by the dark/bright contrast, is quite small compared to the crater diameter. Another crater with a similar diameter at 3.4 km to the northeast also has similar characteristics, which are different from typical craters with smooth bowl-shaped cavities and long, bright rays.

The physical properties of target materials, in this case the lava flow layers, and projectile itself, can change the final crater shape and boulder distribution. Why are so many boulders found only on the interior? That is a darned good question, and we don't know the answer! Perhaps the basalt is very thin here, and the lower portions of the crater expose underlying unconsolidated (loose) debris supplied as the ejecta from Aitken N crater. The strength difference between a basalt cap and the regolith may play a role in boulder distribution as well. This type of crater occurs in other mare, and their origins are often mysterious. Here is yet another lunar enigma awaiting future exploration!

LROC Wide Angle Camera (WAC) monochrome mosaic of Aitken crater, not far from the central meridian of the Moon's farside. Image center view is located near 16.46°S, 173°E. The star and rectangle indicate the location of the LROC Featured Image and NAC footprint. View the full size LROC WAC context image HERE [NASA/GSFC/Arizona State University].

Explorer this boulder rich crater and its environs on the floor of Aitken in the full NAC frame HERE.

Related posts:
Farside impact!
Ray of boulders
Recent Impact in Oceanus Procellarum
Rubble Pile on Fresh Crater Floor
Crater in Mare Humorum

Tycho's flash-frozen inferno

Tycho in a full Sun, 'low phase' illumination, the crown jewel of a Full Moon on Earth has only its relative youth to distinguish it from many similarly-sized craters of similar origin. - LROC Wide Angle Camera (643 nm) mosaic from seven orbital passes (9061 - 9067) June 11, 2011. Arrow marks location of terraced pools of impact melt detailed below [NASA/GSFC/Arizona State University].

Joel Raupe
Lunar Pioneer, LLP

Hardly rare in scope or origin from similar craters all over the Moon, Tycho stands out like a bright star in the nearside southern Highlands because its bright rays radiate outward over the face of an entire Full Moon. Those rays make Tycho visible to the naked eye on Earth.

At a youthful 109 million years of age, relentless gardening by micrometerors has not yet smoothed the crater's reflective rougher edges, nor has a never-ending rain of charged particles, from the Sun and beyond, merged it's coloration into the background.Later impacts have not superimposed themselves or covered over the flash-frozen record of the mere minutes and hours following the explosive release of kinetic energy that created Tycho.

Tycho under 'high phase' illumination, at sunrise shows it's elevations in stark contrast, without the blinding albedo that tends to blur the immediate area of impact into the much broader area affected by that impact. LROC WAC mosaic, with longitude and latitude lines released by the LROC team last July. The impact melt detailed below, pooled just beyond the southeastern rim in this 130 kilometer-wide field of view, is much easier to see in the full-size original LROC image release, available HERE [NASA/GSFC/Arizona State University].

Among these finer details retained by Tycho are the pools of impact melt on the inner terraces and not far outside the crater's high rim, like the 'paved' pond Surveyor 7 nearly landed on in 1968, seen in the stark beauty of LROC Narrow Angle Camera observations.

The progenitor, the object that struck the lunar highlands and created Tycho threw up a lot of material in those first seconds afterward. Some of this material sped away at escape velocity, casually returning to the surface much later, if ever. Some sped away laterally as an immediate shock wave, carrying with it enough force to clip the tops of mountains on the south edge of Mare Serenitatis, knocking down the bright material of the Tortilla Flats in Taurus Littrow, sampled by Apollo 17 in 1972.

Some of the cloud scooped up by the blast hesitated above the area from where it was lifted and piled back down onto the surface outside the molten scar but most of the height where Tycho formed had to have been there before the explosion. We can tell this from the deep rutted channels carved into the highlands for hundreds of kilometers away from its center. The shape of the lunar surface around Tycho is not defined by what piled up but what remained after thousands of square kilometers of material were gouged away.

Tycho seems nested in a kind of plateau, though the evidence appears to show that this plateau was defined out of the highlands by the impact event that created Tycho. Great three and four kilometer-deep gullies appear to have been scooped out and away by the blast, better seen in this virtual 3D oblique view looking north over the outer southeastern rim of Tycho. LROC WAC (643 nm) mosaic as an overlay upon the Kaguya (SELENE-1) lunar digital elevation model in Google Earth [NASA/GSFC/USGS/JAXA/Arizona State University/Google].

The terraces on the inner walls of Tycho became a place for impact melt to pool and cool, so the terraces, by and large, were unlikely to have been formed by later slumping. We're left with a picture, immediately after the Tycho impact event, of a ragged scar, glowing hot in those first hours, from the central peak of deeper rock that rebounded in a heap (never higher than a crater's rim) to the very lip of the outer rim. It must have been a scene right out of Dante's Inferno.

LROC Wide Angle Camera (WAC) monochrome (643 nm) observation M119950214M, LRO Orbit 2810, February 4, 2010; resolution 66.12 meters per pixel, incidence angle 64.73° from 47.55 km. The yellow rectangle roughly outlines the field of view within the entire from of the LROC Narrow Angle Camera (NAC) frame from which scenes following originated [NASA/GSFC/Arizona State University].

Zooming in on these "Southeast Tycho" impact melt ponds, in the images above and following, note the fan of these ponds seem to flow downhill from a particularly ragged spot on the rim and apparently from further north channeled from an less distinct portion of the circumference of Tycho's rim. It's hard to imagine Tycho filled to the "brim" with molten rock, though the original melt was probably higher before it solidified to its present level. 

It's easier to imagine very hot material briefly pasted on the inside walls of Tycho sliding down to pool and form the ponds on the inner wall terraces. The ponds on the outside of Tycho are relatively sparse, but so is the slope acreage elevations outside the crater's interior. Before the anatomy of Tycho cooled and hardened some of the hottest melt was slung high seems to have collapsed like the opening rip of an ocean wave, which quickly froze, liquid rock that fossilized forty million years before the KT Boundary Extinction event brought an end to the Age of Dinosaurs here on Earth.

As impact melt briefly ran down the exterior side of the southeast brim of Tycho and pooled, coming to a halt in the cold vacuum of space long before 'finding its own level,' what appear as grooves formed by flowing molten material appear closer in to be shattered rock that instead merely aided molten transport. LROC NAC observation M150578086R, LRO Orbit 7324, January 25, 2011; resolution 71 centimeters per pixel, incidence angle 69.84° from 44.74 kilometers [NASA/GSFC/Arizona State University].

Full resolution view of the pond shore at the upper northeast in the image immediately above. The impact melt that ponded here briefly 109 million years ago was still hot enough for gas trapped within to heave bubbles to its surface. The flow at this juncture was arriving from all direction and the rounded surface tension elsewhere testifies to the lava-like viscosity of the pond [NASA/GSFC/Arizona State University].

A second full-resolution view from LROC NAC M150578086R shows where melt from the Tycho event briefly flowed down a huge, powerful fall at a high slope between ponds more than a thousand meters apart in elevation [NASA/GSFC/Arizona State University].

Tycho may be the same as many other craters on the Moon, but it's relative youth "in Moon years" makes it an easy choice for mapping the immediate aftermath of a powerful impact on an airless body, at least for the next half billion years or so.

Related Posts:
Tycho Peak Spectacular!
Chaotic crater floor in Tycho
Polygonal fractures on Tycho ejecta
Impact melt on Tycho floor
Ejecta on Tycho floor