Lunar Pioneer

"Ka Pow!" on Joliot's central peaks

noreply@blogger.com (Joel Raupe) — Tue, 18 Jun 2013 20:20:00 +0000

High-reflectance ejecta and low-reflectance impact melt streamers surround this fresh impact crater on the slopes of the central peak formation of Joliot crater. LROC Narrow Angle Camera (NAC) mosaic M189994606R, LRO orbit 13048, April 25, 2012; field of view 2.25 km, 43.12° angle of incidence at 1.11 meters per pixel resolution, from 147.53 km [NASA/GSFC/Arizona State University].

Lillian Ostrach
LROC News System

High-reflectance ejecta blankets the terrain surrounding a 650 meter diameter crater (26.525°N, 93.518°E).

From samples collected during the Apollo missions we know that high-reflectance ejecta represents recently exposed material that has not yet been affected by space weathering processes (maturity rays) or material exposed that is a different composition than the surrounding area (compositional rays).

The impact crater in the opening image formed near the base of the central peak of Joliot crater (172.79 km in diameter, 25.79°N, 93.39°E), the floor of which was partially flooded with volcanic material. What type of ejecta rays are observed in today's Featured Image - compositional or maturity?

LROC WAC monochrome mosaic of the central interior of Joliot crater, with a fresh impact (arrow) at the base of the central peak complex [NASA/GSFC/Arizona State University].

The crater formed on the base of the central peak which is likely highlands material. The rays extend outward more than two crater diameters onto the mare material. Thus we have an example that is both a maturity ray and compositional ray. Over time as the ejecta matures, the portion on the highlands material will be indistinguishable, while the portion on the mare will still be visible. The much larger crater Tycho (93 km diameter) shows the same combination maturity-compositional rays.

Explore the full LROC NAC image for yourself; HERE. Do you see evidence for impact melt and if so, what do you see (ponds, streamers, flows)?

Related Posts:
Polka-dot Ejecta
Ejecta Starburst
Symmetric Ejecta
Ejecta Sweeps The Surface
Minty Fresh

Revealed Surface, eastern Mare Insularum

noreply@blogger.com (Joel Raupe) — Thu, 13 Jun 2013 21:24:00 +0000

Southern slope of unnamed fracture along the eastern mare/highland boundary of Mare Insularum. LROC Narrow Angle Camera (NAC) frame M1114199297R, LRO orbit 16439, January 30, 2013; 1147.2 meter field of view centered on 13.135°N, 355.638°E, 42.94° angle of incidence, resolution 0.96 meters per pixel from 114.18 km. (Downslope toward upper-right, north at top) [NASA/GSFC/Arizona State University].

Hiroyuki Sato
LROC News System

Today's Featured Image highlights a portion of an unnamed linear fissure located along the eastern edge of Mare Insularum, near the mare/highland boundary.

The width of this fissure varies from about 1.5 to 2 km, its length is about 90 km, and it extends in the northwest-southeast direction.

The upper-right portion of the opening image, showing a shallow groove extending from up to middle right of the image, corresponds to the bottom of the fissure. Thus most of the image reveals the southern wall of the fissure.

The LROC Featured Image field of view rendered approximately in elevation data from the LROC WAC DTM. Local slopes in the vicinity of the fracture of interest can be difficult to otherwise see. LROC QuickMap [NASA/GSFC/DLR/Arizona State University].

On this slope, there is a high reflectance area with sinuous boundaries. This unit is hard to interpret in terms of what is on top and what is below, stratigraphically. The sunlight is from left side, highlighting what appears as a slightly raised boundary between the two units (arrows). Elsewhere it looks as if the high reflectance material overlies the lower reflectance material. Which unit is younger? Try counting craters between the two, but be careful, if the units have different hardnesses, then the more coherent unit may preserve craters better.

Unnamed fracture running northwest to southeast on the eastern side of Mare Insularum and surrounding vicinity in LROC WAC monochrome mosaic (100 meters per pixel), centered is 13.12°N, 355.66°E. The LROC NAC footprint (blue box) and location of the field of view in the Featured Image (yellow arrow) are marked [NASA/GSFC/Arizona State University].

Since this whole area is on a slope, slope failure may have revealed an underlying immature surface. Indeed multiple higher reflectance boulders are sitting at the downslope side of this high reflectance unit. But the upper complicated shapes are difficult to explain by this simple story. Or perhaps low reflectance materials could have slumped and covered portions of the high reflectance material? A high resolution NAC DTM would help scientist unravel this complicated morphology.

Explore this enigmatic patterned surface in full NAC frame yourself, HERE.

Related Posts:
Inside Hyginus Crater
Bright ridge near Mons Hansteen
Wrinkle Ridge vs. Impact Crater
Really Wrinkled
Boulders In The Sea Of Serenity
Ghost crater in Mare Imbrium
Zebra Stripes
Aitken Central Peak, Seen Obliquely
Constellation Region of Interest at Mare Tranquillitatis

Layer of Pyroclastics in Sinus Aestuum

noreply@blogger.com (Joel Raupe) — Wed, 12 Jun 2013 22:29:00 +0000

Northeastern wall of Bode C crater. LROC NAC M139938121L, a 600 meter field of view centered on 12.276°N 355.165°E; LRO orbit 5756, 0.50 meters resolution from 46.26 km. Downslope toward bottom right, north at top [NASA/GSFC/Arizona State University].

Hiroyuki Sato
LROC News System

Today's Featured Image highlights the slope of the northeastern crater wall inside Bode C.

The Bode C crater is 7 km in diameter, and located at eastern edge of Mare Insularum.

Low reflectance material flowed down the middle of the wall, possibly indicating a subsurface layered structure of low reflectance materials along this elevation.

High sun (15.07° angle of incidence) over Bode C, in context of a full width mosaic of both the left and right frames of LROC NAC M139938121LR [NASA/GSFC/Arizona State University].

Dark streaks are found along an almost constant elevation throughout the whole crater. Thus the spatial extent of this layer is likely more than the crater diameter.

Bode C in relation to the Rima Bode pyroclastics of Sinus Aestuum, from the Chang'e-1 global medium resolution mosaic [CNSA/CLEP].

Rima Bode, one of many Dark Mantle Deposits (DMD), is located about 20 km east from this crater. DMDs are thought to be formed as fire fountaining eruptions spread ash around a vent. The size of Rima Bode is about 70 by 80 km, with a crescent shape extending northwest and southwest direction. If this DMD distributed ash to the west, Bode C could have excavated this layer of Rima Bode's pyroclastics, thus explaining the dark streaks on its crater wall. High resolution images of impact craters give scientists a lot of information about the crater itself, but also tell about the surrounding geologic structures and history.

LROC WAC monochrome mosaic (100 m/pix), centered on 6.14°N, 177.60°E. The NAC footprint (blue box) and location of opening image field of view (yellow arrow) are indicated [NASA/GSFC/Arizona State University].

Explore the streaks of low reflectance materials inside Bode C in full NAC frame, HERE.

Related Posts:
Rima Bode: Constellation Region of Interest
Pyroclastic Trails
Hyginus Crater and Pyroclastics
Dark Wisps in Copernicus
Dark streaks in Diophantus crater
Low Reflectance Deposits on the Lassell Massif
DMD Excavations
Pyroclastic Excavation

CRaTER on LRO shows lighter materials may better mitigate cosmic ray health risks

noreply@blogger.com (Joel Raupe) — Wed, 12 Jun 2013 15:52:00 +0000

As CRaTER, flying with LRO, closes out a fourth year in lunar orbit, long duration exposure to cosmic rays while traveling within and beyond Earth's magnetic field shows materials lighter than traditional aluminum and titanium alloyed hulls may reduce the probability of Radiation Exposure Induced Death (REID) [NASA/GSFC/UHN/SwRI].

University of New Hampshire - Durham –- Space scientists from the University of New Hampshire (UNH) and the Southwest Research Institute (SwRI) report that data gathered by NASA’s Lunar Reconnaissance Orbiter (LRO) show lighter materials like plastics provide effective shielding against the radiation hazards faced by astronauts during extended space travel. The finding could help reduce health risks to humans on future missions into deep space.

Aluminum has always been the primary material in spacecraft construction, but it provides relatively little protection against high-energy cosmic rays and can add so much mass to spacecraft that they become cost-prohibitive to launch.

The scientists have published their findings online in the American Geophysical Union journal Space Weather. Titled “Measurements of Galactic Cosmic Ray Shielding with the CRaTER Instrument,” the work is based on observations made by the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on board the LRO spacecraft. Lead author of the paper is Cary Zeitlin (zeitlin@boulder.swri.edu) of the SwRI Earth, Oceans, and Space Department at UNH. Co-author Nathan Schwadron of the UNH Institute for the Study of Earth, Oceans, and Space is the principal investigator for CRaTER.

“This is the first study using observations from space to confirm what has been thought for some time—that plastics and other lightweight materials are pound-for-pound more effective for shielding against cosmic radiation than aluminum," Zeitlin said. "Shielding can’t entirely solve the radiation exposure problem in deep space, but there are clear differences in effectiveness of different materials.”

The plastic-aluminum comparison was made in earlier ground-based tests using beams of heavy particles to simulate cosmic rays. “The shielding effectiveness of the plastic in space is very much in line with what we discovered from the beam experiments, so we’ve gained a lot of confidence in the conclusions we drew from that work,” says Zeitlin. “Anything with high hydrogen content, including water, would work well.”

The space-based results were a product of CRaTER’s ability to accurately gauge the radiation dose of cosmic rays after passing through a material known as “tissue-equivalent plastic,” which simulates human muscle tissue.

Prior to CRaTER and recent measurements by the Radiation Assessment Detector (RAD) on the Mars rover Curiosity, the effects of thick shielding on cosmic rays had only been simulated in computer models and in particle accelerators, with little observational data from deep space.

The CRaTER observations have validated the models and the ground-based measurements, meaning that lightweight shielding materials could safely be used for long missions, provided their structural properties can be made adequate to withstand the rigors of spaceflight.

Since LRO’s launch in June 2009, the CRaTER instrument has been measuring energetic charged particles— often very heavy and spectacularly energetic particles traveling at nearly the speed of light and cause detrimental health effects—from galactic cosmic rays and solar particle events (SPE's).

Fortunately, Earth’s thick atmosphere and strong magnetic field provide adequate shielding against these dangerous high-energy particles.

To view the Space Weather article (behind academic pay wall), visit http://onlinelibrary.wiley.com/doi/10.1002/swe.20043/abstract

For more on the CRaTER instrument, visit http://crater.sr.unh.edu/ and for the LRO mission visit http://lunar.gsfc.nasa.gov/mission.html.

CRaTER team at UNH

Cosmic Ray threat to manned spaceflight tested on MSL (May 31, 2013)

The radiation environment and its effects on human
spaceflight: A Lunar Mission (January 5, 2013)
Cosmic ray flux effects lunar ice (March 19, 2012)
"a perfect storm of cosmic rays" (September 29, 2009)
Cosmic rays and manned space travel (September 16, 2009)
Cosmic ray flux highest ever recorded (September 3, 2009)
Returning to the Moon (August 9, 2009)
LUNAR-TEX radiation blanket: Skeptical (May 11, 2009)
NASA cataract detection down to Earth (January 18, 2009)
NASA and Congress sacrifice radiation shielding flexibility
by removing dry landing hardware (May 17, 2008)

Managing Space Radiation Risk in the New Era of Space Exploration (2008)
Committee on the Evaluation of Radiation Shielding for Space Exploration
National Research Council

Slope Resurfacing

noreply@blogger.com (Joel Raupe) — Tue, 11 Jun 2013 20:17:00 +0000

Southeastern wall of Jansen U crater. LROC Narrow Angle Camera (NAC) observation M188028576R, spacecraft orbit 12773 April 2, 2012; 18.45° angle of incidence, resolution 0.98 meters from 120.28 km, 1182.3 meter-wide field of view centered on 11.926°N, 32.306°E (Downslope toward upper left, north at top) [NASA/GSFC/Arizona State University].

Hiroyuki Sato
LROC News Service

Today's Featured Image highlights the wall of Jansen U crater, located at the northeast section of Mare Tranquillitatis. Jansen U is a 3.28 km diameter crater with a teardrop shaped cavity, and likely originated from a low angled oblique impact (see next NAC context image).

The high reflectance area includes many boulders is the crater wall. The low reflectance area in the lower right of the image, which includes a smaller crater (~130 m in diameter), is the rim and shallowly sloping ejecta blanket. The upper left corner of the image, which is covered by low reflectance materials (but not as low as the background surface), corresponds to the crater floor.

Jansen U crater in NAC context image, center on 11.955°N, 32.304°E, field of view about 4 km. The Featured Image corresponds to the field of view outlined by the white box [NASA/GSFC/Arizona State University].

Jansen U crater has an eye-catching appearance due its ovoid shape and brilliant contrast between the low reflectance floor higher reflectance crater walls. Since no indication of impact melt is seen on the crater floor (e.g. fractures or viscous flow features), the floor is likely covered by post impact in-filling materials. Little by little space weathering produces the mature regolith everywhere on the surface, while the slope failure slumps mature material away continuously. These mass wasting and weathering processes often result in striking albedo patterns.

Jansen U and surrounding Mare Tranquillitatis in LROC WAC monochrome mosaic (100 m/pix), centered on 6.15°N, 16.17°E. The NAC footprint (blue box) and the location of the field of view in the LROC Featured Image (yellow arrow) are indicated [NASA/GSFC/Arizona State University].

Explore Jansen U crater, contrasting reflectance patterns of the wall and the floor in the full NAC frame, HERE.

Related Posts:
Downhill Creep or Flow?
Leathery vs smooth surface
Slope failure near Aratus crater
Crater Covered With Boulders!
Bright ridge near Mons Hansteen
Multiple Flow Lobes

Lunar Orbiter images last seen 47 years ago

noreply@blogger.com (Joel Raupe) — Mon, 10 Jun 2013 23:48:00 +0000

Lunar Orbiter 2 frame 159 (H2), an approximately 4.5 by 6 kilometers stretch of lunar mare 250 km southwest of Copernicus. One of three high-resolution photographs swept up, developed, scanned and radioed back to Earth in 1966. The fully-restored, previously incomplete session has been restored by the Lunar Orbiter Image Restoration Project (LOIRP).

Keith Cowing
LOIRP

After being forgotten for nearly 47 years, three high resolution images taken by the Lunar Orbiter II spacecraft have been rediscovered by the Lunar Orbiter Image Recovery Project (LOIRP).

It is unlikely that anyone has seen these images since they were sent back to Earth. Indeed, it is unlikely that very many people saw them at that time either.

The three high resolution images were taken along with a medium resolution image on 23 November 1996 at 17:05:39 GMT. The center point of the images was 26.94 West Longitude, 3.196 degrees North Latitude. The images were taken at an altitude of 43.6 km and the image resolution is 0.93 meters.

Thumbnail of the medium resolution image, from the Lunar and Planetary Institute catalog. The area captured at high resolution in November 1966 is outlined at center. The area seen in "H2" above is outlined in yellow. This region is characterized by ejecta and secondary craters, primarily radiant from the Copernicus impact from 250 km northeast.

We recently came across these three images (#2159) and noticed that they do not appear online at the LPI Lunar Orbiter database. Only the medium resolution image gets mentioned at LPI.

These three images were retrieved from original Lunar Orbiter program analog data tapes yet they appear nowhere in NASA's publications. They do appear on microfilm archives at LOIRP and are mentioned in a simple data log online at LPI. LOIRP has a more extensive computer printout of this data that shows more detail about the images - but not the images themselves.

Among the highest resolution Wide Angle Camera images of the region, among LROC images thus far released to the Planetary Data System (PDS), the area of interest is smaller than a postage stamp, above the right (east) central edge of this 32.4 km-wide field of view from LROC Wide Angle Camera (WAC) observation M166025782C (604 nm), LRO orbit 9601, July 23, 2011; 62.86° angle of incidence, resolution 55.85 meters per pixel from 40.64 km [NASA/GSFC/Arizona State University].

Unless someone happened to be looking through this microfilm collection (LOIRP has the only extant copy) then it is pretty safe to assume that no one has actually seen these images since a technician saw them on a TV monitor in 1966.

Read the full article, catch up on the Lunar Orbiter Image Restoration Project,
and discover how you can help, HERE.

Giordano Bruno Whorl

noreply@blogger.com (Joel Raupe) — Fri, 07 Jun 2013 23:57:00 +0000

Impact melt forms a swirled feature in Giordano Bruno crater. Field of view 1 kilometer. From LROC Narrow Angle Camera (NAC) observation M143947267L LRO orbit 6347, November 9, 2010; 53.08° angle of incidence, 57 centimeters per pixel resolution from 54.50 km [NASA/GSFC/Arizona State University].

Sarah Braden
LROC News System

The crater Giordano Bruno (22 km, 35.97°N, 102.89°E) is a favorite of lunar scientists due to its relatively young age and the amazing impact melt features found within and without the crater walls.

Previously, the LROC Featured Image gave a birds eye view of the whole crater in "Giordano Bruno, The Big Picture."

Today's Featured Image uses a 57 cm per pixel NAC frame to highlight the details of a giant swirl (or whorl) of impact melt within one of the larger impact melt pools inside Giordano Bruno.

Under a much higher Sun, a lower angle of incidence, the 'whorl' (left of center, at the contact between the west crater wall and floor) can also be seen in this mosaic showing nearly the entire complex melt flows and interior of Giordano Bruno. View the full resolution (9587x13223) mosaic, HERE. LROC NAC mosaic M1102880536LR, orbit 14851, September 21, 2012; 37.55° angle of incidence, resolution 1.52 meters from 152.11 km [NASA/GSFC/Arizona State University].

The whorl formed in a clockwise direction and is about 1 kilometer in diameter. This spiral-shaped feature may have formed due to shear stress created when molten impact melt flowed at different speeds (probably caused by drag from the pool floor or an obstacle within the pool). This shear would modify flow directions in ways that could ultimately produce such a swirling pattern. Slumping material may have set the melt into motion within an otherwise calm impact melt pool.

Giordano Bruno from south, looking ahead from Japan's Kaguya (SELENE-1) in polar orbit (2008), from roughly 100 km over the 102nd meridian. The crater is closely studied because it is strikingly fresh, perhaps less than 10 million years old and far less affected by the steady gardening of micrometeorites and the steady rain of energetic cosmic rays that turn over the top 3 mm of the Moon's surface every 2 million years [JAXA/NHK/SELENE]. View the full 1920x1200 original, HERE.

The more information lunar scientists can gather about how quickly impact melt cools, the more we will know about how this structure formed!

Explore the entire NAC frame for more amazing views of Giordano Bruno, HERE.

Related Images:
Very Oblique View of Giordano Bruno
Sunset Over Giordano Bruno
Outside of Giordano Bruno
Fragmented Impact Melt
Impact Melt Flows on Giordano Bruno

Imbrium Bench Crater: Regolith all the way down?

noreply@blogger.com (Joel Raupe) — Thu, 06 Jun 2013 02:08:00 +0000

A small crater hides a bench of bedrock within its walls. Boulders sit just outside the rim. LROC Narrow Angle Camera (NAC) observation M162447033R, LRO orbit 9074, June 11, 2011; 78° angle of incidence, resolution 0.78 meters per pixel, image field of view 800 meters across from 37.5 km [NASA/GSFC/Arizona State University].

Drew Enns
LROC News System

Today's Featured Image shows a bench crater in the lunar mare. Bench craters are so called because they have a small bench lining the interior of the crater wall. In fact, this bench is interpreted to be the contact between the bottom of the regolith and the basaltic bedrock below.

The regolith is a layer of brecciated material that develops as a result of micrometeorite bombardment, it consists mostly of a fine powder containing numerous angular fragments.

The regolith and the coherent basalt both have different strengths, with the regolith being easier to displace than the underlying basalt during an impact event. The result of a moderate impact (in this case one that produced a 160 meter diameter crater) into this area then gave us a spectacular view of the local stratigraphy.

Another Narrow Angle Camera view of the unnamed crater of interest in Mare Imbrium, from a higher altitude later in the LRO mission. LROC NAC frame M190738110R, orbit 13152, May 4, 2012; 52.37° incidence angle, resolution 1.44 meters from 145.83 km [NASA/GSFC/Arizona State University].

Context LROC Lunaserv view showing the location of the small unnamed crater of interest, east-southeast of McDonald crater in Mare Imbrium. The bench crater is near the center of Mare Imbrium at 30.165° N, 339.493°E. Image width is 100 km [NASA/GSFC/Arizona State University].

Regolith development takes time, and many meteor impacts. Since the impact flux (the number of meteors and comets hitting the Moon) has not been constant in the past, the mare have a thinner regolith than the highlands.

Can you find any more bench craters in the full LROC NAC, HERE?

Related Posts:
New Impact Crater on the Moon!
Regolith on Basalt
Fresh Bench Crater in Oceanus Procellarum

LADEE arrives at Wallops Island

noreply@blogger.com (Joel Raupe) — Wed, 05 Jun 2013 18:44:00 +0000

Special Delivery. The Moon-bound LADEE lunar orbiter arrives at NASA Goddard's Wallops Flight Facility, Wallops Island, Virginia [NASA].

NASA - The Lunar Atmosphere and Dust Environment Explorer (LADEE) arrived today at NASA’s Wallops Flight Facility to begin final processing for its trip to the moon later this year. LADEE is a robotic mission that will orbit the moon to gather detailed information about the lunar atmosphere, conditions near the surface and environmental influences on lunar dust. A thorough understanding of these characteristics will address long-standing unknowns, and help scientists understand other planetary bodies as well. LADEE has three science instruments and one technology demonstration onboard.

LADEE’s scheduled September 5 launch will mark several firsts. LADEE will be the first payload to launch on a U.S. Air Force Minotaur V rocket integrated by Orbital Sciences Corporation and the first deep space mission to launch from NASA’s Goddard Space Flight Center’s Wallops Flight Facility.

NASA’s Science Mission Directorate in Washington funds the LADEE mission, a cooperative effort led by NASA’s Ames Research Center. ARC in California is responsible for managing the mission, building the spacecraft and performing mission operations.

NASA’s Goddard Space Flight Center in Maryland is responsible for managing the science instruments and technology demonstration payload, and the science operations center.

Wallops Flight Facility is responsible for launch vehicle integration, launch services, and launch range operations.

NASA’s Marshall Space Flight Center in Alabama manages LADEE within the Lunar Quest Program Office.

For more information about the LADEE Mission, visit: http://www.nasa.gov/LADEE

LADEE ready to baseline the dusty lunar exosphere and test high-speed data link

noreply@blogger.com (Joel Raupe) — Wed, 05 Jun 2013 16:50:00 +0000

Idealized view of LADEE, last of the Constellation 'precursors,' in lunar orbit [NASA/ARC].

Steve Nerlich
AmericaSpace.com

The Lunar Atmosphere and Dust Environment Explorer (LADEE) is due for launch in September 2013 from the Mid-Atlantic Regional Spaceport. LADEE will study the composition and structure of the tenuous lunar atmosphere, including dust that may be lofted up from the surface. It will also undertake a demonstration of a laser-mediated communications system.

In a thick atmosphere like Earth’s, particles are constantly colliding with each other and hence moving in random and frequently-changing directions. The Moon is thought to have a surface boundary exosphere, which is a thin, collision-free atmosphere in which particles follow largely uninterrupted paths.

A key goal of the LADEE mission is to understand the dynamics of a surface boundary exosphere and how it changes over time, as external conditions vary. A surface boundary exosphere is probably the most common atmosphere found around celestial bodies in the Solar System, including Mercury, the majority of the large asteroids, the moons around our major planets, and the majority of large Kuiper Belt Objects. So, getting a better understanding of the Moon’s surface boundary exosphere is a good start to understanding those environments as well.

Indeed, there is a certain imperative to undertake this research now. The increasing interest in the Moon by a number of nations will lead to a steadily increasing frequency of lunar exploration missions that could change the natural composition of the lunar atmosphere, both through the stirring up of surface dust and by the addition of rocket exhaust components.

Read the article at AmericaSpace.com, HERE.

Related Posts:

First laser comm system ready for launch on LADEE (March 16, 2013)
LADEE project manager update (February 6, 2013)
The Mona Lisa test for LADEE communications (January 21, 2013)
Expectations for the LADEE LDEX (March 23, 2012)
LADEE architecture and mission design (July 6, 2010)
NASA applies low cost lessons to LADEE (January 18, 2010)
LADEE launch by Orbital from Wallops Island (April 14, 2009)

Spinning for the Prize

noreply@blogger.com (Joel Raupe) — Wed, 05 Jun 2013 16:01:00 +0000

"The Spirit of California," a design with unique heritage. A spin-stabilized Google Lunar X-Prize contender-that-was [Southern California Selene Group].

Rex Ridenoure
The Space Review

Five years ago, one of the then-active Google Lunar X PRIZE teams quietly signed off, withdrew from the competition, and ceased operations. At the time, it was arguably considered the team to beat in the quest for the prize. This article summarizes that team’s story and highlights a novel advancement in lander architecture derived from this short-lived yet very effective effort.

A long wait

This story starts fifty years ago at Hughes Aircraft Company in Southern California (Culver City), where Dr. Harold A. Rosen, a 37-year-old experienced and clever electrical engineer and radar expert, was leading a small team of engineers putting together what became the first successful series of geosynchronous communications satellites, Syncom. A few years prior, Rosen floated the idea to Hughes management of designing and launching a small, simple spinning satellite to GEO as part of the US response to the USSR’s 1957 Sputnik launch. This project would also serve as a kick-start toward the vision of global GEO satellite connectivity first articulated by Arthur C. Clarke in his seminal 1945 Wireless World article.

Syncom 1 was launched in February of 1963 and achieved the desired orbit, but suffered an immediate electrical failure. Five months later, Syncom 2 was successfully launched and began operating nominally. Syncom 3 repeated the achievement a year later.

During 1962–1963, while Rosen and his team were immersed in their Syncom work, Hughes was bidding to be the prime contractor for NASA’s planned series of robotic lunar landers, Surveyor. The Caltech/NASA Jet Propulsion Laboratory had already developed a notional design for the lander and was looking to the emergent US space industry to complete the detailed design and then build the spacecraft.

Rosen was asked to peer review his firm’s proposal, and came away unimpressed. “That design was so big and clunky, and so expensive,” he recounted some 45 years later. “I knew back then that there was a much more elegant and cost-effective way to land.”

Read the article at The Space Review, HERE.

GSFC releases LEND lunar water demonstration

noreply@blogger.com (Joel Raupe) — Mon, 03 Jun 2013 17:20:00 +0000

Map of energetic neutron absorption near the lunar South Pole, showing the places where water ice is most likely to be found, built up and trapped for aeons in areas of extreme cold and darkness. Interestingly, not all the permanently shadowed regions show strong detection of hydrogen atoms while some areas that do receive at least some sunshine do register such a presence. Note the strong indication at Cabeus, chosen late in the LCROSS mission as its impact target in 2009. [NASA/GSFC/SVS/Roscosmos].

NASA has released a new video, prepared by the Science Visualization Studio (SVS) at Goddard, highlighting the Lunar Exploration Neutron Detector (LEND) and results of data that instrument has built up since it arrived in orbit with the Lunar Reconnaissance Orbiter (LRO) three years ago.

The new SVS video is a popular introduction the role of LEND as part of the LRO mission, not a comprehensive report of results except to show how data was methodically collected over many months in polar orbit.

Though not without some controversy, regarding its resolution and final value, the Russian LEND - a highly anticipated follow-up to Lunar Prospector (1998-1999) - has now orbited over the Moon's north and south poles 18,000 times. The instrument has measured absorption of neutrons scattered from the surface below, indicating the possible presence of water ice or other volatile hydrogen compounds at the Moon's high latitudes.

The press release discussion of the new LEND video reads, "Since the 1960's, scientists have suspected that frozen water could survive in cold, dark craters at the Moon's poles. While previous lunar missions have detected hints of water on the Moon, new data from the Lunar Reconnaissance Orbiter (LRO) pinpoints areas near the south pole where water is likely to exist. The key to this discovery is hydrogen, the main ingredient in water: LRO uses its Lunar Exploration Neutron Detector, or LEND, to measure how much hydrogen is trapped within the lunar soil. By combining years of LEND data, scientists see mounting evidence of hydrogen-rich areas near the Moon's south pole, strongly suggesting the presence of frozen water."

Related Posts:
LRO LEND: "A Scientific Dispute" (March 27, 2012)
Will LRO LEND prove effective? (February 21, 2012)
Where are the wettest places on the Moon (October 23, 2010)
LRO analysis of LCROSS impact proves essential (October 21, 2010)

Cosmic ray threat to manned spaceflight tested on MSL

noreply@blogger.com (Joel Raupe) — Fri, 31 May 2013 02:09:00 +0000

The MSL cruise phase as unmanned proxy for Orion, testing the deep space radiation environment [NASA].

Employing present, proven technology manned space travel to Mars exceeds NASA’s own limits on astronaut radiation exposure. That limit is calculated in terms of risk of “Radiation Exposure Induced Death,” or “REID,” over an individual astronaut’s life expectancy.

Ironically, as astronauts age their risk of eventually dying from causes unrelated to radiation exposure steadily increase. It’s the kind of risk coldly calculated by insurance providers. Though dying of undiagnosed heart disease is fed into the calculus, such other threats to the older astronaut's long-term survival overshadow their cumulative risk of REID.

None of this is news. This fly in the ointment in need of being overcome before humans can safely experience long-duration spaceflight beyond Earth’s magnetic field was starkly spelled out in the influential “ (2007),” a report put together by the National Academy of Science before the Constellation program was cancelled. The hard numbers have been gathered from the opening of the Space Age, from Explorer 1 through Apollo, from the Voyagers through the International Space Station.

Now these projections have been verified again by an instrument that traveled to Mars with Curiosity.

The lead investigators for these sensors announced their results during a NASA audio press conference Thursday. Dr. Cary Zeitlin, a principal scientist in the Southwest Research Institute’s (SwRI) Space Science and Engineering Division discussed detailed measurements of energetic and highly-ionizing particle radiation gathered during the 253 day, 560 million km journey to deliver the Mars Science Laboratory (MSL) “Curiosity” rover to the floor of Gail crater on Mars.

The Radiation Assessment Detector (RAD) made detailed measurements of the energetic particle radiation environment inside the spacecraft, providing important insights for future human missions to Mars.

NASA/JPL/SwRI

"In terms of accumulated dose, it's like getting a whole-body CT scan once every five or six days," said Dr. Cary Zeitlin, a principal scientist in SwRI's Space Science and Engineering Division and lead author of Measurements of Energetic Particle Radiation in Transit to Mars on the Mars Science Laboratory, scheduled for publication in the journal Science on May 31.

"Understanding the radiation environment inside a spacecraft carrying humans to Mars or other deep space destinations is critical for planning future crewed missions," Zeitlin said. "Based on RAD measurements, unless propulsion systems advance rapidly, a large share of mission radiation exposure will be during outbound and return travel, when the spacecraft and its inhabitants will be exposed to the radiation environment in interplanetary space, shielded only by the spacecraft itself."

Titanium alloy in the hull of a manned spacecraft is a good shield
against most solar particle events, but counter-productive against
the heaviest cosmic rays. These heavy nucleons split and shower
damage into human tissue.

Two forms of radiation pose potential health risks to astronauts in deep space: a chronic low dose of galactic cosmic rays (GCRs) and the possibility of short-term exposures to the solar energetic particles (SEPs) associated with solar flares and coronal mass ejections. Radiation dose is measured in units of Sievert (Sv) or milliSievert (1/1000 Sv). Long-term population studies have shown that exposure to radiation increases a person's lifetime cancer risk; exposure to a dose of 1 Sv is associated with a 5 percent increase in fatal cancer risk.

GCRs tend to be highly energetic, highly penetrating particles that are not stopped by the modest shielding provided by a typical spacecraft. These high-energy particles include a small percentage of so-called heavy ions, which are atomic nuclei without their usual complement of electrons. Heavy ions are known to cause more biological damage than other types of particles.

The solar particles of concern for astronaut safety are typically protons with kinetic energies up to a few hundred MeV (one MeV is a million electron volts). Solar events typically produce very large fluxes of these particles, as well as helium and heavier ions, but rarely produce higher-energy fluxes similar to GCRs. The comparatively low energy of typical SEPs means that spacecraft shielding is much more effective against SEPs than GCRs.

"A vehicle carrying humans into deep space would likely have a 'storm shelter' to protect against solar particles. But the GCRs are harder to stop and, even an aluminum hull a foot thick wouldn't change the dose very much," said Zeitlin.

"The RAD data show an average GCR dose equivalent rate of 1.8 milliSieverts per day in cruise. The total during just the transit phases of a Mars mission would be approximately .66 Sv for a round trip with current propulsion systems," said Zeitlin. Time spent on the surface of Mars might add considerably to the total dose equivalent, depending on shielding conditions and the duration of the stay. Exposure values that ensure crews will not exceed the various space agencies standards are less than 1 Sv.

"Scientists need to validate theories and models with actual measurements, which RAD is now providing. These measurements will be used to better understand how radiation travels through deep space and how it is affected and changed by the spacecraft structure itself," says Donald M. Hassler, a program director at Southwest Research Institute and principal investigator of the RAD investigation. "The spacecraft protects somewhat against lower energy particles, but others can propagate through the structure unchanged or break down into secondary particles."

Only about 5 percent of the radiation dose was associated with solar particles, both because it was a relatively quiet period in the solar cycle and due to shielding provided by the spacecraft. Crew exposures during a human mission back and forth to Mars would depend on the habitat shielding and the unpredictable nature of large SEP events. Even so, the results are representative of a trip to Mars under conditions of low to moderate solar activity.

"This issue will have to be addressed, one way or another, before humans can go into deep space for months or years at a time," said Zeitlin.

SwRI, together with Christian Albrechts University in Kiel, Germany, built RAD with funding from the NASA Human Exploration and Operations Mission Directorate and Germany's national aerospace research center, DLR.

Scientific Context for the Exploration of the Moon (2007)
Space Studies Board
National Research Council

Origin of lunar MASCONS found in GRAIL data - JPL

noreply@blogger.com (Joel Raupe) — Thu, 30 May 2013 22:17:00 +0000

The Moon's elusive, uneven gravity is clearly seen in this Free-Air Gravity map produced from data returned in 2012 by the twin GRAIL orbiters. Mare Imbrium, for example, at upper right presents a significant anomalous profile, concentrated near what may have been the original "transitory" crater boundary but equally reduced from the lunar average (blue) between that boundary and the outer reaches of Imbrium's present boundary [NASA/JPL/MIT].

Pasadena -- Investigators combing through the huge treasure trove of data returned to Earth by NASA's GRAIL (Gravity Recovery and Interior Laboratory) twin spacecraft Ebb and Flow in 2012 claim to have "uncovered the origin of massive invisible regions that make the moon's gravity uneven, a phenomenon affecting the stability and longevity of lunar-orbiting spacecraft," JPL announced Thursday.

"GRAIL data confirm that lunar mascons were generated when large asteroids or comets impacted the ancient moon, when its interior was much hotter than it is now," said Jay Melosh, a GRAIL co-investigator at Purdue University in West Lafayette, Ind., and lead author of the new research. "We believe the data from GRAIL show how the moon's light crust and dense mantle combined with the shock of a large impact to create the distinctive pattern of density anomalies that we recognize as mascons."

The origin of lunar mascons has been a mystery in planetary science since their discovery in 1968 by a team at NASA's Jet Propulsion Laboratory in Pasadena, Calif. Researchers generally agree mascons resulted from ancient impacts billions of years ago. It was not clear until now how much of the unseen excess mass resulted from lava filling the crater or iron-rich mantle upwelling to the crust.

On a map of the moon's gravity field, a mascon appears in a target pattern. The bulls-eye has a gravity surplus. It is surrounded by a ring with a gravity deficit. A ring with a gravity surplus surrounds the bulls-eye and the inner ring. This pattern arises as a natural consequence of crater excavation, collapse and cooling following an impact. The increase in density and gravitational pull at a mascon's bulls-eye is caused by lunar material melted from the heat of a long-ago asteroid impact.

"Knowing about mascons means we finally are beginning to understand the geologic consequences of large impacts," Melosh said. "Our planet suffered similar impacts in its distant past, and understanding mascons may teach us more about the ancient Earth, perhaps about how plate tectonics got started and what created the first ore deposits."

"Mascons also have been identified in association with impact basins on Mars and Mercury," said GRAIL principal investigator Maria Zuber of the Massachusetts Institute of Technology in Cambridge. "Understanding them on the moon tells us how the largest impacts modified early planetary crusts."

Launched as GRAIL A and GRAIL B in September 2011, the probes, renamed Ebb and Flow, operated in a nearly circular orbit near the poles of the moon at an altitude of about 34 miles (55 kilometers) until their mission ended in December 2012. The distance between the twin probes changed slightly as they flew over areas of greater and lesser gravity caused by visible features, such as mountains and craters, and by masses hidden beneath the lunar surface.

Truncated Rille in Jules Verne

noreply@blogger.com (Joel Raupe) — Thu, 30 May 2013 20:00:00 +0000

A lunar rille comes to an abrupt termination at a crater rim (34.342°S, 145.430°E). LROC Narrow Angle Camera (NAC) frame M1122636898R, LRO orbit 17626, May 8, 2013; illumination from east-northeast, an approximate 1 km wide field of view at 0.74 meters resolution [NASA/GSFC/Arizona State University].

James Ashley
LROC News System

We invite you to take a close look at this sinuous rille in Jules Verne crater on the lunar farside.

Why do we see it approach this portion of an ancient, mare-flooded crater rim and suddenly terminate?

Any flowing river of molten rock (the process responsible for most sinuous rilles) would skirt the base of such a positive-relief structure once encountered ... unless the crater rim formed after the rille. But if the crater is flooded by mare basalts (see context image below) the crater must have formed before the rille, which established itself during mare emplacement.

Simple contextual seven kilometers wide field of view shows a wide distribution of debris aprons bordering nearly every contact zone in the vicinity of this ghost crater on the floor of Jules Verne. View a much larger rendition HERE. LROC NAC mosaic M192002047LR, orbit 13328, May 18, 2012; 66.47° angle of incidence, resolution 0.72 meters per pixel from 70.65 km [NASA/GSFC/Arizona State University].

LROC Wide Angle Camera (WAC) mosaic covering a 100 km wide field of view, including the western interior of Jules Verne [NASA/GSFC/Arizona State University].

A clue may be present within the rille itself. Note the sloping wall of debris entering the rille at the point where it encounters the crater wall near the center of the Featured Image. This is accumulated debris, which has been shed from the crater rim. If you look closely at the full NAC frame, HERE, you can also see a subtle break in slope around the perimeter of the crater wall that betrays the presence of a debris apron or pediment.

This eroded material may have buried other portions of rille that might indeed have skirted the original rim, giving the visible portion an appearance of protruding out of the rim at a sharp angle. Can you find any additional clues that would help solve the puzzle?

Other examples of rilles are highlighted in the LROC Featured Image posts "Meanders in Posidonius," "The Old and the Young in Tsiolkovskiy," and "Rimae Prinz Region - Constellation Region of Interest."

"Star light, star bright"

noreply@blogger.com (Joel Raupe) — Wed, 29 May 2013 18:56:00 +0000

A sharp reflectance contrast is found in an unnamed crater on the east floor of Humboldt (26.593°S; 83.764°E). NAC frame M182974061L, illumination is from the west, north is up, image is ~850m wide [NASA/GSFC/Arizona State University].

James Ashley
LROC News System

Why do we see such a sharp contrast in reflectance in the above Featured Image between the crater wall on the left and the crater floor on the right? This is the floor and wall of an ~8.5-km diameter, unnamed impact crater within the much larger Humboldt crater on the lunar farside.

The reason for the striking dichotomy in terrain appearance is not a mystery -- it has to do with solar illumination angle.

Our star, the Sun is shining from the west at an elevation above the lunar horizon (~25°) that is close to the slope of the western crater wall. Thus much of the wall on this side is receiving low-angle sunlight and appears relatively dark compared to the crater floor surface, which is more directly illuminated. The floor makes a clean contact with the crater walls, and becomes a zone of deposition for boulders rolling down the slope, including one larger and prominent boulder at the southern end of the frame.

Contextual view of the unnamed crater of interest (center) on the far east floor of Humboldt, its interior and floor highly illuminated by a comparatively low angle of solar illumination (a high Sun). From the global albedo lunar photograph mosaic swept up over the mission of China's lunar orbiter Chang'E-2 [CNSA/CLEP]..

For reasons like this, planetary scientists need to be careful when making interpretations of surface features, and must often use several images collected under a variety of lighting geometries to understand the geomorphology.

The entirety of Humboldt crater, from the early LROC GLD100 Wide Angle Camera (WAC) global mosaic. The unnamed crater of interest is designated [NASA/GSFC/Arizona State University].

The WAC mosaic presents the exotic landscape of Humboldt crater for context. Click HERE to see the full NAC frame.

Other examples of lighting effects can be found at the earlier LROC Featured Image posts, Shadows in Egede A, Boulder or Crater?, and Sunset Boulder.

Alien materials found in lunar crater! (Film at Eleven)

noreply@blogger.com (Joel Raupe) — Wed, 29 May 2013 17:40:00 +0000

Central peaks of Copernicus - covered by fairy dust? -- From oblique LROC Narrow Angle Camera (NAC) mosaic M193025138LR, LRO orbit 13472, May 30, 2012; field of view is a 1350 pixel section from a spectacular LROC mosaic revealing the 90 km-wide interior of the landmark lunar crater, HERE [NASA/GSFC/Arizona State University].

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

Accuracy in scientific reporting (and thus the education of the public) is wholly dependent on a reporter’s understanding of the material they’re covering. Making a reporter’s job even more challenging is the fact that some research results themselves can be misleading.

A variant of my post title above appeared recently over a story reporting the results of a paper published in the journal Nature Geoscience. That study used computer modeling to simulate the effects of a low velocity impact on the Moon. Computer models of natural phenomena are made in an attempt to understand complex processes that we could otherwise not be able to address.

To briefly set the stage on this new work, we believe that the vast majority of craters on the Moon and planets are formed by the collision of solid objects with these bodies. These impacts occur at very high speeds; on the Moon, the average velocity of impact is about 20,000 meters per second. At such speeds, geological materials will vaporize and the mechanics of the formation of a crater are complex. These results have been painstakingly described through laboratory and field studies of both natural and artificial impact craters of a wide range of sizes.

Because we needed to fully understand the mechanics of impact cratering to understand the record in the Apollo lunar samples, much work was conducted toward characterizing the physical and chemical effects of impact on typical rocks. Because impact velocities are typically high, there is little preservation of the projectile in impact craters. Most of the impactor is vaporized and this super-hot silicate vapor is partly lost to space and partly incorporated into the shock melted rocks of the crater interior.

"For every problem there is a solution that is simple, elegant and wrong." - Mencken

The soils returned from the Apollo missions contained a recognizable fraction of material that must have been added by the impacting objects that created its craters. In most soils, this fraction is on the order of a few weight percent. Interestingly, this “meteoritic component” tends to be defined chemically and actual fragments of meteorite in the lunar soil are extremely rare. This observation would seem to support the notion that most of the impacting debris is vaporized at impact and does not occur as fragments on the surface.

However, the speed of impacting projectiles cited above is an average speed, meaning that while some impacts occur at higher velocities, others must occur at lower speeds. As the encounter velocity decreases, there is an increasing likelihood that some portions of the impacting fragments might be preserved on the surface. It is this last possibility that the new paper considers. The authors modeled the effects of the impact of a relatively slow-moving body with the Moon and found that more fragments of the object are preserved than in high velocity impacts. Moreover, by tracing the paths of impactor particles during cratering flow, they find that much of this preserved material ends up on or near the central peak of the resulting crater.

That last finding is interesting because in remote sensing studies of the lunar surface, it is in the central peaks where we find “unusual” compositions, in the sense that those compositions are different from the average upper lunar surface. The traditional explanation for this relation is that because central peaks are derived from well below the impact target, they are exposing deep-seated compositions (lower levels of the crust of the Moon contain different rock types than occur on the surface). The study’s new interpretation suggests instead that the central peaks are covered in debris from the impacting projectile.

One problem with this interpretation is that the “debris covering” of central peaks should occur in a distinct minority of craters (i.e., those created by low velocity impacts). But the exposure of unusual compositions within central peaks of lunar craters is quite common and occurs globally. Moreover, there are as many impacts at higher velocity as at lower velocity. Yet slow impacts would produce less total volume of impact melt and most of the central peak craters on the Moon have abundant melt deposits.

Central peaks of the farside landmark crater Tsiolkovskiy, from over 200 km to the west of the highest promontory. The large, mare-inundated impact crater was very unlikely to have been formed by a "low-velocity" collision. A highly reduced in scale crop from a LROC NAC mosaic, M1098059280, orbit 14176, July 27, 2012; resolution between 4.6 and 5.3 (background) meters, from 87.66 km over 20.44°S, 121.42°E. Enlargement, HERE [NASA/GSFC/Arizona State University].

The most serious flaw in the new study is the assumption that the “unusual minerals,” olivine and spinel (found in many central peaks), are rare on the Moon. They are not rare; although spinel is somewhat sparse on the lunar surface (requiring high pressure for its formation), it has been described as present in lunar rocks from the first sample return and more recently has been found in remote sensing data of impact basin deposits.

Olivine is a very abundant mineral on the Moon and typically makes up a significant fraction of the dark mare basalts (including some lavas that consist only of olivine and glass.) Olivine is also not uncommon in highland rocks, usually occurring within the rock type troctolite, a 50-50 mixture of olivine and plagioclase. The presence of olivine does not indicate either “deep” origins or “lunar mantle” provenance; virtually all olivine in lunar samples has high calcium content, indicating a relatively shallow origin (probably in magmas that crystallized within a few kilometers of the surface).

In short, there is no compelling reason to believe that the central peaks of many lunar craters are dusted with exotic minerals from asteroids, although such a possibility is certainly not excluded. The minerals that we see in central peaks are all indigenous to the Moon and in some cases, abundant in the lunar crust.

Computer modeling in science has both value and pitfalls. An impact event is extremely messy and complicated. Simultaneously, gigantic shock pressures and temperatures occur, putting billions of particles in motion. Computers are good at keeping track of these particles and the codes developed to model complex, multi-variable phenomena have been shown to at least partly describe the behavior of crater formation on Earth. However, the results of computer models must be interpreted cautiously; small changes in input variables or the conditions of the simulation sometimes result in drastic changes in the output of the model. In addition, there is a tendency in science to believe in numbers, regardless of their provenance. Because a model holds together does not mean that it describes reality.

In science, it is dangerous to embrace a model because it “works” (i.e., comes to closure). Much of the current fracas over human-induced climate change comes from those who contend that the results of computer models constitute “settled science” (whatever that is). Because the computer models say that it may happen, people assume (and some journalists report) that it is happening. In actual fact, we have no direct observational evidence that human-caused emissions of carbon dioxide are causing the climate to change. That conclusion comes from computer models that “show” (project) that humanity’s introduction of “excess” carbon dioxide into the atmosphere by industrialization will increase the magnitude of the greenhouse effect and raise the mean global temperature. But climate (like impact) is a complex, chaotic phenomenon and we still do not fully understand how the Earth’s atmosphere interacts with itself and the cosmos.

In questions of complex natural processes, beware of accepting the results of computer modeling too easily. Computer models are useful tools, but the old software adage of “garbage in, garbage out” still applies. Be familiar with whom and from where the information comes, understand how it is processed and then carefully consider the likelihood of reported accounts.

Originally published May 29, 2013 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 but are better informed than average.

Coalescing Secondaries

noreply@blogger.com (Joel Raupe) — Tue, 28 May 2013 19:53:00 +0000

A chain of impact features provides a picturesque tableau (48.659°N; 103.299°E). LROC Narrow Angle Camera (NAC) frame M18286833R, LRO orbit 12051, February 3, 2012; illumination is from the southwest (angle of incidence 63.07°), north is up, image field of view approximately 2 km across [NASA/GSFC/Arizona State University].

James Ashley
LROC News System

Today's Feature Image exhibits a chain of impact features that are so closely spaced as to lose their distinction as separate landforms, producing one continuous feature instead.

An asymmetry in the ejecta pattern can also be seen in the form of filamentary tendrils extending to the north.

Based on this ejecta distribution, the secondary bolides likely came from a southerly or southeasterly direction.

Another, earlier look at the same field of view, at slightly higher resolution. LROC NAC M123901314R, orbit 3393, March 22, 2010; angle of incidence 47.54° at 0.56 meters resolution from 53.96 km [NASA/GSFC/Arizona State University].

The WAC mosaic context image is approximately 83 km wide [NASA/GSFC/Arizona State University].

Zooming out to learn what this source might have been produces no obvious candidates, however. None of the medium-sized craters within 40 km of the featured crater chain appear to be particularly young -- a condition required to explain the chain's fresh appearance. Not until we expand our view even further do likely candidates crop up.

This larger scale WAC mosaic context image is just about 470 km wide [NASA/GSFC/Arizona State University].

But even here nothing unambiguous catches the eye. The secondary impacts could have resulted from one of any number of craters, or perhaps from an impact located even further away. A detailed surface study would be necessary before a definitive link could be made tying this ejecta with its crater of origin. Explore the full NAC frame HERE.

Other examples of ejecta interactions with the lunar surface can be found in Crater Chain near Rima T Mayer, Four of a Kind in Catena Davy, and Four Leaf Clover.

Bonus Context: The location of the field of view shown at high resolution in the LROC Featured Image, released May 29, 2013 in the north farside highlands. The terrain is representative of one of the four recognized lunar material groups, the farside anorthositic highland terrain, or FaHT [NASA/GSFC/SVS].

Eimmart A: a Crater of Contrasts

noreply@blogger.com (Joel Raupe) — Sun, 26 May 2013 22:02:00 +0000

John Moore

His latest YouTube video 3D tour,
of crater Eimmart A.

Eimmart A is a relatively small (7.34 km), fresh-looking crater that impacted close by the east rim and ejecta of crater Eimmart (23.97°N, 64.8°E, 44.99 km in diameter).

The impactor that produced Eimmart A may have initially struck on an odd 'contact point': between where ejecta from Eimmart, at its west, met the lava-flooded floor of Mare Anguis (associated to formation of the Crisium Basin), at its east.

As a consequence, a wonderfully, bowl-shaped crater formed where material excavated from it was shot out in every direction - whose signatures, today, mainly shows up particularly as bright rays emanating away from the crater (observable through any amateur-sized telescopes ~ 4-inch or greater).

Huge reduction of a slightly oblique (slew -9.52°) LROC Narrow Angle Camera (NAC) observation of Eimmart A. (Full Resolution NAC mosaic can be viewed HERE.). LROC NAC M1098408548LR, LRO orbit 14225, July 31, 2012; illumination incidence angle 50.96° at an overall average resolution of 1.46 meters per pixel, from 140.93 km over 24.14°N, 66.53°E [NASA/GSFC/Arizona State University].

Close-up of the crater, and its inner walls, displays a 'contrast of sorts'! On the eastern side, we see dry-debris flows of materials that have 'slid' down towards the crater's floor, while on its western side, sheets of melted rock have solidified on the surface, in place

Why the contrast? Why do dry debris flows on one side of the crater contrast against melts on the other side?

New (above) and slightly older (Google/USGS/JAXA) digital elevation models show the anatomy of the Eimmart A impact on the east rim of Eimmart. The view above derived from the LROC QuickMap WAC/NAC GLD100 DEM, below LROC WAC monochrome image overlaid upon the USGS DEM derived from Japan's Kaguya and the United State's DOD Clementine laser range topography.

An oblique impact scenario might be presumed; where the impactor came in at a low angle from the east; whose main energy then produced a predominance in melting on the westwards (down-range), western-side wall. But such impacts usually result in asymmetric-shaped craters -- like in what we see at crater Proclus, an others.

But Eimmart A certainly isn't asymmetric: it is perfectly, circularly-formed from what we would expect by an impactor coming in at a high angle. So what would have produced the 'contrast of sorts'?

Eimmart A from above, in an image used to illustrate the LROC Featured Image "Rootless Impact Flows," July 26, 2011. LROC WAC monochrome (643 nm) observation M119415370M, spacecraft orbit 2732, January 29, 2010; 64.5 meters resolution from 46.4 km [NASA/GSFC/Arizona State University].

The wider region in the vicinity of Eimmert A (above left center), under a higher Sun, shows the wider range of the younger crater's bright ejecta (and the darker material of its interior). From a LROC WAC mosaic stitched from four sequential orbital passes, May 8, 2011 [NASA/GSFC/Arizona State University].

Would it be that the impactor, on impact, encountered a more 'harder' surface (the lavas of Mares Anguis) at its eastern side, and a more 'softer' surface (Eimmart's ejecta) at its western side? If so, each side may have had a different, rock-melt gradient (that is, a difference in melting because of previous, dynamically-altering of material events), which might explain the resultant contrast of dry debris versus melt in Eimmart's walls that we see.

In an above average eyepiece (actually a stacked mosaic, more specifically "Matsutov-Cassegrain Santel D=230mm F=3000mm, Mount WS-180GTl Unibrain Fire-i 702 CCD black and white camera (1388x1040 pixels); filter: Baader IR-pass 685nm+ stacking in AutoStakkert! 2, Deconvolution in Astra Image; Mosaic of 17 images") Eimmart A in line-of-sight-from-Earth context. Image by Yuri Goryachko, Mikhail Abgarian and Konstantin Morozov of Astronominsk, Minsk, Belarus, January 29, 2012.

Whatever the scenario, while Eimmart itself is impressive enough in the eyepiece, Eimmart A is really the 'eye-candy', the 'stealer', the one that we should appreciate more - given from what we see in this flyover.

HD Recomended.

Related:
Rootless impact melt flows (July 26, 2011)

Project Morpheus Tether Test 21

noreply@blogger.com (Joel Raupe) — Fri, 24 May 2013 22:30:00 +0000

This was "the first tether test of the v1.5b," Project Morpheus Bravo vehicle. The video runs about 29 seconds.

"We had a good ignition and climb. However, as the vehicle attempted to stabilize itself it exceeded the internally set boundary limit causing a soft abort."

Related Posts:
Morpheus Unit B first fully integrated hot fire test (May 6, 2013)
Morpheus and ALHAT teams, still hard at work (February 11, 2013)
Morpheus employs ALHAT in teather test #16 (June 13, 2012)
Project Morpheus lander - Soft Abort Test (May 11, 2012)
Morpheus Tether Test #10 (April 9, 2012)
Morpheus Tether Test #8 (March 14, 2012)
Project Morpheus methane Hot Fire Test #5 (February 29, 2012)
Morpheus lander in tethered flight tests (May 7, 2011)

Layers of Imbrium excavated by Caroline Herschel Crater

noreply@blogger.com (Joel Raupe) — Thu, 23 May 2013 19:11:00 +0000

Exposed mare basalt layering in the wall of Caroline Herschel crater (34.48°N, 328.71°E). LROC Narrow Angle Camera (NAC) observation M175475137R, spacecraft orbit 10994, November 9, 2011; field of view 350 meters at 45 cm per pixel resolution; angle of incidence 55.93° from 30.15 km [NASA/GSFC/Arizona State University].

Sarah Braden
LROC News System

Outcrops of layered mare basalt are visible in the interior wall of Caroline Herschel crater (located at 34.48°N, 328.71°E, in western Mare Imbrium).

The mare basalt layers were exposed during the excavation phase of the impact which created this 13.7 km diameter crater. Some debris from the crater rim and the wall have fallen over the layers but the structure of the outcrop is still preserved.

The crater is superposed on a north-south trending wrinkle ridge which is visible in the LROC WAC context image below. This crater is named after Caroline Herschel, an astronomer and half of the sister/brother science team with astronomer Sir William Herschel.

Wider angle view of the northwestern rim, wall and interior of C. Herschel. LROC NAC M1106123678L, orbit 15305, October 29, 2012; resolution 1.5 meters per pixel, angle of incidence 53.18° from 150.4 km [NASA/GSFC/Arizona State University].

Caroline discovered several comets, and in 1828 the Royal Astronomical Society awarded her their Gold Medal for her work. She made observations, kept detailed records, performed complex mathematical calculations, and polished her own telescope mirrors. Caroline has multiple comets named after her as well as the lovely lunar crater in today's Featured Image.

LROC Wide Angle Camera (WAC) context for Caroline Hershel. The white asterisk marks the area of basalt layering in the Featured Image. Field of view is 48 kilometers [NASA/GSFC/Arizona State University].

Explore the entire NAC frame to see the beauty of the Moon, HERE.

Related Images:
Galilaei's Layered Wall
Pytheas
Dawes
Lava Flows Exposed in Bessel Crater

Pit Crater in Fecunditatis

noreply@blogger.com (Joel Raupe) — Thu, 23 May 2013 02:18:00 +0000

What may be a newly resolved "pit crater," similar to at least three other unique features found elsewhere on the Moon. This one is near the equator in Mare Fecunditatus (0.92°S, 48.66°E). The nearly circular 110 meter-wide opening may or may not narrow in diameter further into its interior. LROC Narrow Angle Camera (NAC) observation M1107960917R, (at 180%) LRO orbit 11562, November 19, 2012; angle of incidence 62.93° from 108 km [NASA/GSFC/Arizona State University].

Joel Raupe

Lunar Pioneer

It’s time to inventory the Moon’s “pit craters.” The first, the "Haruyama," or "Marius Hills pit crater" (14.065°N, 303.224°E) is in a sinuous rille immediately west of the famous shield volcano range in Oceanus Procellarum.

A second and third have now been found and photographed from many angles, in Mare Tranquilitatis (8.34°N, 33.22°E) and Mare Ingenii (35.95°S, 166.06°E), respectively.

It appears the LROC team at Arizona State University uncovered another, over the past year, out on the vast equatorial plains of Mare Fecunditatis (0.92°S, 48.66°E).

This is remarkable for a number of reasons, not least among them the mission’s elapsed time. As of this writing LRO has completed 17,801 orbits around the Moon. Without knowing the exact percentage of the lunar surface yet to be photographed by the LROC Narrow Angle Cameras – it’s remarkable a 110 meter wide target could have been missed until relatively recently.

That is it might seem remarkable, until we consider some basic “beta angles,” so to speak, some basic mission priorities and logistics.

Location of a possible pit crater in a 155 km-wide field of view of northwest Mare Fecunditatis. LROC QuickMap 250 meter per pixel resolution [NASA/GSFC/Arizona State University].

The target is within a single degree south of the equator. Obviously a spacecraft in polar orbit is going to see its orbital pathways and targeting opportunities converge directly over the poles, conversely those same opportunities will be at their greatest distance apart at the equator.

A closer look through one particularly fine set of LROC Wide Angle Camera passes over target (arrow), the feature is just visible in this imperfectly merged monochrome (604 nm) WAC mosaic swept up during three sequential orbital passes; from 47.4 km altitude. Resolution roughly 55 meters, 63° angle of incidence; field of view a little over 40 km, from west to east [NASA/GSFC/Arizona State University].

Secondly, this has got to be one of the Moon’s great “Rub’ al khali's,” an empty quarter, which must have seemed nearly void of inviting targets, with very inviting targets nearby, particularly to the west, where the fascinating Messier and Messier A craters reside. The east rim of Messier B is only a little over 20 kilometers directly to the west. The desire, even the need, to slew the spacecraft and camera’s off nadir to examine these and other nearby targets is reason enough for the pit to have been overlooked.

Then there’s the target itself, which brightens considerably between a 30° and 0° angle of incidence. Under the highest sun, near noon, and again, very near the equator, the target looks like what it may in fact be: an unusual but still rather commonplace nearly fresh crater.

It proves, yet again, that there are still great new discoveries yet to be made on the Moon.

Raw rendition of the LROC NAC observation which may have touched off further interest in a new "target of opportunity," in the months that followed. The pit crater in Mare Fecunditatis shows up on the very edge of this frame from orbit 13087, April 28, 2012. LROC NAC M190280022L, 62.93° angle of incidence, 1.09 meters resolution from 108.01 km [NASA/GSFC/Arizona State University].

Having to guess just what drew their interest, the target seems to have been photographed at high resolution April 28, 2012, in orbit 13087. Amazingly, the pit was nearly missed. You can see the north half of the target at the very top of LROC Observation M190280022L, HERE.

By last fall it seems the pit was directly targeted under three lighting conditions, the first, last September, must have seemed disappointing. With the Sun only five degrees from directly overhead what little topography might be seen on target and in the region may have seemed washed out in shadowless albedo contrasts. If this was a pit crater the “ledge,” if any, was not overshadowing.

First full close-up released to the PDS shows a brightly lit interior, and little to no depth. But the Sun was high, and the location less than a degree south of the equator. LROC NAC M1103245601L, orbit 14902, September 25, 2012, angle of incidence 7.765° at 0.94 meters resolution, from 108.88 km [NASA/GSFC/Arizona State University].

A month later the Sun was a little more favorable. LROC NAC M1105602888L, orbit 15232, October 23, 2012; angle of incidence 35.18° at 0.93 meters resolution from 108.28 km [NASA/GSFC/Arizona State University].

After yet another month, the mid-morning Sun is at an even greater angle. Shown at its original resolution, this is the image at the top of the post. LROC NAC M1107960917R, orbit 15562, November 19, 2012; angle of incidence 62.93° at 1.1 meters resolution, from 108.01 km [NASA/GSFC/Arizona State University].

Related Posts:
Impact melt collapse pit (March 2, 2012)
Failed Skylights of Copernicus (January 24, 2012)
New view of Sinas pit crater (November 11, 2011)
Sublunarean Void (February 7, 2011)
New views of lunar pits (September 14, 2010)
How common are mare pit craters? (July 15, 2010)

Concentricity in Apollo Basin

noreply@blogger.com (Joel Raupe) — Wed, 22 May 2013 20:18:00 +0000

Portion of an unnamed concentric crater in Apollo Basin. Sun is incident from the right to the left. LROC Narrow Angle Camera (NAC) mosaic M1122245918LR, orbit 17571, May 3, 2013; image field of view is 6.3 km [NASA/GSFC/Arizona State University].

Sarah Braden
LROC News System

The double-arch shape in the Featured Image is a portion of an unnamed concentric crater located in the northwestern extent of Apollo Basin (basin center at 35.687°S, 208.232°E).

The concentric crater has an inner ring, centered on 30.757°S, 205.931°E, a middle ring, and then the crater rim.

The crater formed within the mare basalt that fills Apollo Basin. The formation mechanism for concentric craters like this one is not entirely clear. One theory is that the target material is made of multiple stratigraphic layers with different strengths. If the difference between the strengths of the layers is great enough, the impact may form concentric rings.

Bench craters also form when target layer strengths are different.

Oblique NAC view of the unusual crater morphology in Apollo basin. LROC NAC mosaic M109753923LR, orbit 14102, July 21, 2012; camera and spacecraft slew off nadir 57.74° resolution roughly 2 meters per pixel from 76.2 km over 31°S, 200.62°E [NASA/GSFC/Arizona State University].

In the late 1960s laboratory experiments replicated the concentric shape of craters using targets with loose, granular material over stronger, more cohesive layers. The laboratory experiments use different materials and are at smaller scales than their lunar counterparts. Still, experiments like these are important for comparing what we see on the lunar surface to basic physical principles. What if an impact occurs in an area with highland material as one layer and then mare basalt as a second layer? What crater shape is produced if you introduce a regolith layer? These are the questions that lunar geologists use to design their experiments.

LROC WMS Wide Angle Camera mosaic of the concentric crater in context with north and northwestern Apollo basin, The crater of interest is 11.5 km across [NASA/GSFC/Arizona State University].

Explore the entire LROC NAC mosaic, HERE

Related Images:
Concentric Crater (Gruithuisen K)
Apollo Basin: Mare in a Sea of Highlands
Small Pond
LOLA's Apollo Basin
Biggest, deepest crater - an excavation of the hidden, ancient Moon

March of Time Paces Changes on the Lunar Surface

noreply@blogger.com (Joel Raupe) — Tue, 21 May 2013 04:36:00 +0000

New Crater - small white blotch, with black center (in center of image), is likely a new impact crater formed during the LRO mission (since June 2009). Inset in lower left, a closer look at a 38 meter wide field of view, a 4x enlargement from unreleased LROC Narrow Angle Camera (NAC) observation M1117799545; full field of view above is 480 meters wide [NASA/GSFC/Arizona State University].

Mark Robinson
Principal Investigator
Lunar Reconnaissance Orbiter Camera
Arizona State University

Impacts are the most important force shaping the surfaces of planets, moons, asteroids, and comets. In fact small asteroids and comets impact the Earth and Moon every day. On Earth, most of these small bolides burn up in the atmosphere and can be seen at night as meteors (aka shooting stars). Larger meteoroids hit the surface as fragments, or intact. Recall the recent meteor that exploded over Chelyabinsk Russia, and caused minor, yet widespread damage. That meteor was thought to be 15 to 20 meters in diameter before breaking up, fortunately the atmosphere absorbed most of the energy of that event. More recently in the news, a much smaller object was seen to impact the Moon on 17 March 2013. A team of Marshall Space Flight Center scientists photographed this bright flash (and many others), and then computed latitude and longitude coordinates.

Temporal Comparison - Before and after LROC NAC images showing one of many distinctive white splotches that the LROC SOC team is finding in temporal comparisons [NASA/GSFC/Arizona State University].

The LROC team targets the coordinates of flashes for future observations in hopes of finding a newly formed crater. If an LROC NAC image of the impact area was acquired before the event, it is very likely that the crater can be found by comparing before and after images. If no pre-existing image exists then the task becomes nearly impossible because there are so many small, young impact craters on the Moon! So far the LROC team has found one crater associated with Marshall impact flash reports, certainly more will follow. However, the search is not limited to Marshall targets - in fact the LROC team has found over seventy potential new impact craters that formed since LRO went into orbit.

Temporal sequence - LROC NAC temporal sequence, new crater in center. Width 300 m [NASA/GSFC/Arizona State University].

Why the adjective "potential" in front of "new impact craters"? What we are seeing in most cases are reflectance splotches, some low reflectance and some high reflectance. In only a handful of these observations can a crater be resolved. It is likely in the "other" cases that the crater is simply too small to be resolved in the NAC images, which have pixel sizes ranging from 50 cm to 150 cm. To pick out the crater you need to have at least three to five pixels, depending on lighting conditions. So craters need to be bigger than 1.5 meters (at best) to be resolved. So far, the largest new crater definitively identified in the NAC-to-NAC temporal comparisons is 7 meters (23 feet) in diameter.

Ten changes - LROC NAC image footprint on LROC WAC mosaic background, the red square indicates small (a few meters) changes in the surface over the course of a year [NASA/GSFC/Arizona State University].

In some cases, clusters of new splotches (craters) are seen in the NAC comparisons. What causes the clusters? Perhaps a bolide breaks up due to gravitational forces as it nears the surface? Or maybe these splotches are secondaries formed from a larger nearby primary impact? A search for new craters in the WAC has so far revealed no new larger parent crater, but the search continues.

A great advantage of a long-lived LRO mission is to make such temporal comparisons possible over a statistically significant percentage of the Moon. As the new observations are acquired, more and larger new impacts will be discovered. LROC will image the 17th of March Marshall flash target over the next several opportunities, thus covering the full area (the coordinates are only known to about the width of a NAC pair). If pre-existing NAC images of the impact site exist it should be easy to identify the ejecta in the post-flash image - and perhaps even resolve the crater. Stay tuned!

Closing thought: Similar to the GRAIL impact craters some of the "new" craters may exhibit a low reflectance ejecta blanket. Once again the mysterious Moon turns the table on conventional wisdom!

Related LROC Featured Images:
New crater found NAC image compared to Apollo Pan image
LROC sees GRAIL impact sites!

Brightest impact recorded by NASA lunar monitoring program, March 17

noreply@blogger.com (Joel Raupe) — Fri, 17 May 2013 12:57:00 +0000

Impact with kinetic energy equivalent to 5 tons of TNT, March 17, 2013. Still from NASA ScienceCast released May 17. The event was the brightest of recorded over eight year span of NASA lunar impact monitoring program. Video still shows the nearside's earthshine-lit western hemisphere at the moment of impact, in the southern tier of Mare Imbrium, north by northwest of Copernicus [NASA/Science].

Dr. Tony Phillips
Science@NASA

For the past 8 years, NASA astronomers have been monitoring the Moon for signs of explosions caused by meteoroids hitting the lunar surface. "Lunar meteor showers" have turned out to be more common than anyone expected, with hundreds of detectable impacts occurring every year.

They've just seen the biggest explosion in the history of the program.

"On March 17, 2013, an object about the size of a small boulder hit the lunar surface in Mare Imbrium," says Bill Cooke of NASA's Meteoroid Environment Office. "It exploded in a flash nearly 10 times as bright as anything we've ever seen before."

Anyone looking at the Moon at the moment of impact could have seen the explosion--no telescope required. For about one second, the impact site was glowing like a 4th magnitude star.

Ron Suggs, an analyst at the Marshall Space Flight Center, was the first to notice the impact in a digital video recorded by one of the monitoring program's 14-inch telescopes. "It jumped right out at me, it was so bright," he recalls.

The 40 kg meteoroid measuring 0.3 to 0.4 meters wide hit the Moon traveling 56,000 mph. The resulting explosion1 packed as much punch as 5 tons of TNT.

NASA's lunar monitoring program has detected hundreds of meteoroid impacts over the eight year formal history of the program. The brightest, detected March 17, in Mare Imbrium, is marked by the red square [NASA/Science].

An impact on the trailing eastern limb of the Moon monitored January 8, 2008.

Cooke believes the lunar impact might have been part of a much larger event.

"On the night of March 17, NASA and University of Western Ontario all-sky cameras picked up an unusual number of deep-penetrating meteors right here on Earth," he says. "These fireballs were traveling along nearly identical orbits between Earth and the asteroid belt."

This means Earth and the Moon were pelted by meteoroids at about the same time.

“My working hypothesis is that the two events are related, and that this constitutes a short duration cluster of material encountered by the Earth-Moon system," says Cooke.

One of the goals of the lunar monitoring program is to identify new streams of space debris that pose a potential threat to the Earth-Moon system. The March 17th event seems to be a good candidate.

Controllers of NASA's Lunar Reconnaissance Orbiter have been notified of the strike. The crater could be as wide as 20 meters, which would make it an easy target for LRO the next time the spacecraft passes over the impact site. Comparing the size of the crater to the brightness of the flash would give researchers a valuable "ground truth" measurement to validate lunar impact models.

Unlike Earth, which has an atmosphere to protect it, the Moon is airless and exposed. "Lunar meteors" crash into the ground with fair frequency. Since the monitoring program began in 2005, NASA’s lunar impact team has detected more than 300 strikes, most orders of magnitude fainter than the March 17th event. Statistically speaking, more than half of all lunar meteors come from known meteoroid streams such as the Perseids and Leonids. The rest are sporadic meteors--random bits of comet and asteroid debris of unknown parentage.

U.S. Space Exploration Policy eventually calls for extended astronaut stays on the lunar surface. Identifying the sources of lunar meteors and measuring their impact rates gives future lunar explorers an idea of what to expect. Is it safe to go on a moonwalk, or not? The middle of March might be a good time to stay inside.

"We'll be keeping an eye out for signs of a repeat performance next year when the Earth-Moon system passes through the same region of space," says Cooke. “Meanwhile, our analysis of the March 17th event continues.”

A few related posts:
LROC team identifies a new lunar crater (July 28, 2010)
Lunar meteor impact observations and the flux of kilogram-sized meteoroids (July 25, 2010)
The Lunar Geminids (December 10, 2009)
Impact Gap in Moon's Southern Highlands? (May 22, 2008)