Showing posts with label Mare Imbrium. Show all posts
Showing posts with label Mare Imbrium. Show all posts

Wednesday, June 18, 2014

Soaring over the Apennines

This is another LROC NAC mosaic viewers may really want to see using the "see all sizes" download option that accompany slideshow images in Flickr. An oblique view, looking west over the Apennine Mountains toward Hadley Rille (above -north is to the right).  The morning shadows are much as they were July 30, 1971, when Dave Scott and Jim Irwin flew on their backs over range at bottom, flipped forward and landed on the broad plain between those hills and Rima Hadley. Hadley Base, their landing site, and the descent stage of the Apollo 15 lunar module Falcon is right where they left it, just within the resolution of full scale reproductions of this image. 
Notable features in a thumbnail of LROC NAC oblique mosaic M1123519889LR, LRO orbit 17751, May 18, 2013; spacecraft and cameras slew 55.22° from orbital nadir, 76.87° incidence angle, average resolution 2.87 meters from 130.27 km over 26.11°N, 11.75°E [NASA/GSFC/Arizona State University].
J. Stopar
LROC News System

Apollo mission planners selected an adventurous landing site for Apollo 15 (26.132219°N, 3.633861°E), on a relatively small patch of lava plains (mare). 

This site is nestled between the towering Apennine mountains to the east, attaining heights of 3-5 km, and the 200 meter deep, v-shaped valley of Hadley Rille to the west.

The experience gained from the successful landings of the preceding Apollo missions afforded mission controllers confidence that a landing descending through a mountain range was possible, though it required a steeper descent angle (25° rather than 14°).

The landing site of Apollo 15 (direct center), on Hadley Rille Delta between the Apennine mountain range on the southeast periphery of Mare Imbrium and Rima Hadley, winding through the distinctly darker mare material of Palus Putredinis. LROC WAC GLD100 elevation overlain atop LROC 100 meter global mosaic. The peaks of the Apennine Mountains rise more than 5 km over the interior of the Imbrium basin [NASA/GSFC/Arizona State University].
A captioned video of the descent of Apollo 15 conveys the excitement of astronauts David Scott and James Irwin as they set down near Hadley Rille. The Hadley Rille landing site also presented an opportunity to test the capabilities of the new lunar roving vehicle (LRV).


"Down on the plain at Hadley." Newly realigned video (3:37) of the landing of Apollo 15, July 30, 1971. [LunarModule5].

The Apennine Mountain Range formed during the Imbrium basin-forming event, and it was hoped these mountains contained materials from very early in the Moon's history (which they did!). As astronauts Irwin and Scott descended over the Apennines, they reported a floating sensation that resulted from glimpsing mountain peaks passing by the windows of the Lunar Module (LM). The descent was a complete success, and the LM set down near the planned site! Although, the astronauts were a little surprised to land with one foot-pad in a small crater, placing the vehicle on a slant.

Cmdr. Dave Scott captured this view of the Apollo 15 lunar module Falcon where it came to rest tilting toward the Apennine mountains beyond, while Jim Irwin checked out the first of the three Apollo "J mission" lunar rovers. See full-size mosaic of two color images from the panorama (AS15-86-11600 and 11601) HERE [NASA/JSC/ALSJ].
Three EVAs (or traverses) were planned for Apollo 15 using the LRV, two of which allowed sampling part of the Apennine Mountain Range to the south and southeast and required long (multi-kilometer) traverses.

Thumbnail of a mosaic of black and white images from Science Station 6, during the second EVA of the Apollo 15 expedition, on the slopes of the "Apennine Front." In the full-size panorama, HERE, the lunar module Falcon is visible, several kilometers away, between Hadley rille on the far left and Mt. Hadley, dominating the center of this mosaic [AS15-85-11481-11492, NASA/JSC/ALSJ].
Astronauts Scott and Irwin were accomplished field geologists; listen HERE as Commander Scott recently reflected on his Apollo 15 experience, including the importance of field-geology training.

The tiny arrow marks the location of the LM, just barely within the resolution of the LROC NAC mosaic (at full-scale), while LRO orbited over a spot 130 km away. Of course, the landing zone has been documented with remarkable detail from LRO, from better vantages [NASA/GSFC/Arizona State University].
Related Posts:

Friday, January 31, 2014

Geologic characteristics: Chang’E-3 exploration region

From extensive data distilled from remote sensing collected by the DIVINER Lunar Radiometer on-board the Lunar Reconnaissance Orbiter (LRO) since July 2009 has allowed David Page and the DIVINER team to produce extensive maps of the thermal behavior "and a range of derived quantities at the Chang'e-3 landing site, described in a separate report released January 5. Distinct areas can be seen in LROC WAC Surveys, with an overlay mapping rock abundance using thermal dissipation temperatures collected at the coldest periods, before local sunrise. DIVINER detected no minimum temperatures in the area below 94°K [NASA/JPL/UCLA/GSFC/ASU].
Zhao, Huang & Qiao, et.al.
Planetary Science Institute
China University of Geosciences, Wuhan

Science China (March 2014)

ABSTRACT: We present topographic, geomorphologic and compositional characteristics of a 1°×1° (~ 660 square kilometer) region centered near the landing site of Chang’E-3 using the highest spatial resolution data available. We analyze the topography and slope using Digital Terrain Model (DTM) generated from Terrain Camera (TC) images. The exploration region is overall relatively flat and the elevation difference is less than 300 meters, and eighty percent of the area slopes are less than 5°. 

Impact craters in the exploration region are classified into four types based on their degradation states. We investigate the wrinkle ridges visible in the exploration region in detail, using TC and Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) images. We calculate iron oxide and titanium dioxide abundances using Multispectral Imager (MI) data and confirm two basaltic units: the northern part, belonging to Imbrium era low-titanium to very-low titanium mare basalts, and the southern part is Eratosthenian era low titanium to high titanium mare basalts. 

Finally, we produce a geological map and propose the geologic evolution of the exploration region. 

M177x3C_604nm-anot-580x800
The north central Mare Imbrium exploration region and landing site of Chang'e-3.  The geology report dates the northern mare to the Imbrium Age and the southern mare, in the lander's immediate vicinity to the Eratosthenian age, two billion years apart. LROC WAC mosaic swept up in three sequential orbits, December 5, 2011; sunrise angle of incidence 76° at 61.5 meters per pixel resolution, from 44.7 km [NASA/GSFC/Arizona State University].
INTRODUCTION: Nearly 40 years after the completion of the Apollo and Luna missions, the third Chinese lunar mission, Chang’E-3 (CE-3), was launched on December 2, 2013 and safely landed on the surface of the Moon on December 14, 2013.

The rover “Yutu” separated from the lander successfully about 8 hours later. The landing site of CE-3 is 44.12°N, 340.49°E, which is located in the northern part of Mare Imbrium. As the first Chinese lunar soft-lander and rover, the landing site was selected primarily considering engineering constraints, including topography, communication and solar illumination.

In addition, local geologic diversity was also taken into consideration, including impact craters, wrinkle ridges, and basaltic materials of different ages. The CE-3 landing site and its nearby terrains have never been visited by any other missions. Therefore, the exploration will shed light on the geologic characteristics, geochemical diversity and evolution of Mare Imbrium.

Geological maps in Apollo era and recent studies reveal regional geologic information for Sinus Iridum and the adjacent terrains. However, the spatial resolution of previous maps is not sufficient for detailed geologic study or for the rover traverse planning considering both scientific and engineering requirements. Luckily, as unprecedented high spatial resolution remote sensing data being acquired by recent lunar missions (e.g., Chang’E 1 & 2, SELENE-1, Chandrayaan-1 and Lunar Reconnaissance Orbiter: LRO), large scale geological mapping and detailed study were possible for prior study of the Chang'e-3 landing site and its exploration region. 

Read or Download the Full Adobe PDF file HERE.

Tuesday, December 31, 2013

Chang'e-3 lander and Yutu rover from LRO

LROC view of Chang'e 3
LROC Narrow Angle Camera (NAC) view of the Chang'e 3 lander and Yutu (Jade Rabbit) rover just before local sunset on their first lunar day of exploring Mare Imbrium. LROC NAC M1142582775R, image field of view 576 meters [NASA/GSFC/Arizona State University].
Mark Robinson
Principal Investigator
Lunar Reconnaissance Orbiter Camera
Arizona State University

Chang'e 3 landed on Mare Imbrium (Sea of Rains) just east of a 450 m diameter impact crater on 14 December 2013. Soon after landing, a small rover named Yutu (Jade Rabbit) was deployed and took its first tentative drive onto the airless regolith. At the time of the landing LRO's orbit was far from the landing site so images of the landing were not possible. Ten days later on 24 December, LRO approached the landing site, and LROC was able to acquire a series of six LROC Narrow Angle Camera (NAC) image pairs during the next 36 hours (19 orbits).

YuTu Rover (58762-717x940)
Yutu in a monochrome still captured from the Chang'e-3 lander, already slumbering in preparation for the bristling cold 14 day lunar night [CNSA/CLEP].
The highest resolution image was possible when LRO was nearly overhead on 25 December 03:52:49 UT. At this time LRO was at an altitude of ~150 km above the site, and the pixel size was 150 cm.

LROC NAC before and after images of the Chang'e 3 landing site [NASA/GSFC/Arizona State University].
The rover is only about 150 cm wide, yet it shows up in the NAC images for two reasons: the solar panels are very effective at reflecting light so the rover shows up as two bright pixels, and the Sun is setting thus the rover casts a distinct shadow (as does the lander). Since the rover is close to the size of a pixel, how can we be sure we are seeing the rover and not a comparably sized boulder? Fortuitously, the NAC acquired a "before" image (M1127248516R) of the landing site, with nearly identical lighting, on 30 June 2013. By comparing the before and after landing site images, the LROC team confirmed the position of the lander and rover, and derived accurate map coordinates for the lander (44.1214°N, 340.4884°E, -2640 meters elevation).

Panorama to LROC Narrow Angle CameraNAC
Chang'e 3 lander panorama [Images from CNSA; compiled by Di Lorenzo and Kremer] showing Yutu shortly after it drove down the ramp to the surface. Yellow lines connect craters seen in the panorama and the LROC image (taken at a later date after the rover had moved), red lines indicate approximate field of view of the panorama.
The lander set down about 60 meters east of the rim of a 450 meter diameter impact crater (40 meters deep) on a thick deposit of volcanic materials. A large scale wrinkle ridge (~100 km long, 10 km wide) cuts across the area and was formed as tectonic stress caused the volcanic layers to buckle and break along faults. Wrinkle ridges are common on the Moon, Mercury and Mars.

change3_wac_morph_and_noslew_1000
LROC WAC context mosaic for the Chang'e 3 landing site (large white arrow); small white arrows indicate wrinkle ridge and small black arrows delimit boundary between "red" mare (northeast) and "blue" mare (southwest), image is 100 km wide [NASA/GSFC/Arizona State University].
M177x3C_604nm-anot-58x128-1337x2950
Another LROC Wide Angle Camera mosaic, captured at high incidence, show the extent of the wrinkle ridge in northwest Mare Imbrium. Area swept up during three sequential orbital passes in 2011. See the full-size mosaic HERE [NASA/GSFC/Arizona State University]/
Lunar mare basalts are divided into two main spectral (color) types: "red" and "blue" (blue is perhaps a misnomer, think "less red"). Basalts on the Moon (same on Earth) are composed mainly of two minerals, pyroxene and plagioclase, though olivine and ilmenite can sometimes occur in significant amounts. The presence of ilmenite (FeTiO3) results in lower reflectance and a "less-red" color - thus the blue basalts. The landing site is on a blue mare (higher titanium) thought to be about 3.0 billion years old. The boundary (black arrows in above WAC mosaic) with an older (3.5 billion years) red mare is only 10 km to the north.

WAC Color Chang'e 3
LROC WAC color (689 nm, 415 nm, 321 nm) overlain on WAC sunset black and white image. Note the proximity of the landing site to a contact between red and blue maria [NASA/GSFC/Arizona State University].
A large area LROC WAC topography map of the Imbrium basin and surrounds is available HERE.

Related LROC Featured Images:
Safe on the Surface of the Moon!
A Great Place to Rove!
LROC Coordinates of Robotic Spacecraft - 2013 Update

Chang'e 3: NAC before and after images
LROC NAC observations before and after, animated above [NASA/GSFC/Arizona State University].

Sunday, December 15, 2013

LRO: Finding Chang'e-3

landing_clean_M102285549La1-1000
In more than four years in lunar orbit, the LRO LROC Narrow Angle Camera (NAC) system has released to the Planetary Data System (PDS) ony a few observations that include the Chang'e-3 landing site. From the earliest of these, acquired July 15, 2009, in only orbit 250 comes this sample of LROC NAC observation M102285549, centered on the area seen in descent images acquired by Chang'e-3 while closing in on the surface of Mare Imbrium. The field of view is 1700 meters, resolution 1.66 meters per pixel, late afternoon angle of incidence 80.85° from 168.17 km [NASA/GSFC/Arizona State University].
Mark Robinson
Principal Investigator
Lunar Reconnaissance Orbiter Camera (LROC)
Arizona State University

Chang'e-3 successfully landed on the Moon on 14 December 2013. The touchdown occurred on the far eastern edge of the commonly reported landing zone (44.12°N, 340.49°E), in the northwestern portion of Mare Imbrium. By correlating features seen in the nested series of Chang'e-3 descent images it appears the spacecraft landed just to the east of a 450 meter diameter crater.

descent_lroc1-3200
Boxes indicate areas in Chang'e-3 descent images. The spacecraft is probably in, or very near, the smallest box. Field of view 4700 meters wide, from LROC NAC M181302794L orbit 11832, January 15, 2012; angle of incidence 71.7° at 1.57 meters resolution, from 158.79 km [NASA/GSFC/ASU/JHUAPL].
The exact landing site will be known when the Chang'e-3 flight team has time to correlate features seen in surface images with orbital images, and tracking data are refined.

sequence
Chang'e-3 descent images used to locate landing site in LROC NAC images [CNSA/CLEP].
LRO will next be above western Mare Imbrium on 24 and 25 December, and LROC will image the Chang'e-3 landing site.

Meanwhile, why not evisit previous LROC posts of other hardware still on the Moon, and check out the LROC Featured Sites, HERE.

Chang'e-3 Landing Site in Mare Imbrium

Chang'e-3 Landing Site
Landing Site of the Chang'e-3 lunar lander located and marked at the center of a full (1.58 meters per pixel) resolution, 916 meter-wide field of view of the surface of Mare Imbrium. The preliminary official landing site was 44.12°N, 19.51°W, though the location marked was matched with sequential still video returned to Earth by Chang'e-3 during its landing sequence. LROC NAC mosaic M183661683RL, orbit 12162, February 12, 2012; angle of incidence 54.12° from 159.26 kilometers [NASA/GSFC/Arizona State University].
Chang'e-3 Landing Site matched with LROC NAC imagery
3.16 km-wide field of view (2000 x 2000 px.), HERE.
Chang'e-3 Landing Site matched with LROC NAC imagery
6.32 km-wide field of view (4000 x 4000 px.), HERE.

See a second LROC NAC observation of the Chang'e-3 landing site, of slightly better resolution, HERE.

Friday, November 15, 2013

The Lunar Alps

Rille in the Montes Alps
A portion from LROC Narrow Angle Camera oblique mosaic M177602135LR, and a rille, seen in the center of this image, running northwest to southeast through the Montes Alpes northwest of Mare Imbrium. Field of view approximately 15 km (north to the right). Spacecraft orbit 11309, December 4, 2011; average resolution 3.12 meters per pixel from 41.6 km over 49.86°N, 4.3°E [NASA/GSFC/Arizona State University].
H. Meyer
LROC News System

Rilles are common on the Moon and are considered one of the most fascinating volcanic features due to their wide range of scales (100's of meters to over 100 kilometers in length) and morphologies they present (linear, arcuate, or sinuous).

Rilles commonly form when lava flows erode into the existing surface through melting of the substrate, mechanical stripping away of material, or a combination of both thermal and mechanical processes. However, some rilles may have been lava tubes that underwent roof collapse since their formation.

The Lunar Alps
An uncorrected full resolution stitch of LROC NAC mosaic M177602135LR, allowing a false perspective on the rille of interest, west of the spacecraft's orbital track [NASA/GSFC/Arizona State University].
M177602135LR-1500x400
A lower resolution, corrected view of the full LROC NAC oblique. The rille discussed in LROC Featured Image released November 15, 2013 indicated by white arrows [NASA/GSFC/Arizona State University].
In Today's Featured Image, lava carved into the surface between peaks of the Montes Alpes ("Alpine Mountains") and left behind a narrow, long depression resembling a meandering terrestrial river channel, complete with what appear to be cut-off meanders (called oxbows on Earth). In this case, the rille developed meanders as the lava flowed around topographic highs, which in this area are the Montes Alpes.

Vallis Alps, Montes Alps
LROC WAC image of Montes Alpes; field of view approximately 500 km across, centered at 49.397°N, 358.731°E. LROC Featured Image area outlined by the red rectangle [NASA/GSFC/Arizona State University].
Montes Alpes, named by the Polish astronomer Johannes Hevelius, is a mountain range formed by the Imbrium impact event, stretching from the crater Plato all the way to the Montes Caucasus. It forms part of the northeastern border between Mare Imbrium and Mare Frigoris. The Montes Alpes range is bisected by Vallis Alpes ("Alpine Valley"), a flat-bottomed valley with a rille running right down the center from Mare Imbrium to Mare Frigoris that can be seen in the WAC context image above. The Montes Alpes separate the two mare; however, Vallis Alpes breaches that boundary. What might that mean for the geologic history of this area?

Explore Montes Alpes and the rille for yourself HERE.

Related Posts:
Discontinuous Rilles
Old Man River (of Lava!)
Montes Pyrenaeus meets Mare Nectaris

Thursday, June 6, 2013

Imbrium Bench Crater: Regolith all the way down?

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

Thursday, January 24, 2013

Almost submerged under Mare Imbrium basalt

Lunar mare basalt flows partially cover a crater. LROC NAC M186105790L, LRO orbit 12504, March 11, 2012; under a high Sun (incidence angle 17.75°) field of view 580 meters, resolution 1.03 meters from 131.69 km [NASA/GSFC/Arizona State University].
Sarah Braden
LROC News System

A crater (located at 17.331°N, 326.544°E) is almost entirely submerged by mare basalt. The remains of the crater indicate that the original crater was about 650-700 meters in diameter. Along the interior crater wall there are materials of different reflectance: high reflectance where boulders cover the crater wall, and low reflectance where mare basalt has flowed down the wall. The relatively low incidence angle of this image, ~18°, makes it easier to see differences in the reflectance of materials. The mare basalt flows filled the crater interior and left a mantle of mare material on the walls. It is unclear if the boulders are from the original crater wall, or if they are boulders from the basalt flow created as the edges of the flow erode away.

Even when mare basalt flows completely submerge a crater evidence of the crater rim can persist. These are called ghost craters (and you can read more about them HERE).

The crater in the Feature Image is east of another mostly submerged crater, T Mayer W (see the WAC context image below). The eastern rim of T Mayer W is the most prominent section above the mare basalt flows. Areas of high reflectance in the WAC context image are actually rays of ejecta from the crater Copernicus, which is more than 470 km away. These rays are an excellent example of how impact processes can effect the geologic context of a site even from a great distance. 

The white box contains the crater in the LROC Featured image released January 24, 2012. LROC Wide Angle Camera (WAC) 100 m/pixel mosaic [NASA/GSFC/Arizona State University].
Explore the entire LROC NAC, HERE.

Related Images:
Young and Old
Ghost crater in Mare Imbrium
The Ghosts of Mare Fecunditatis
Ghost Crater in Southern Mare Crisium

Thursday, November 15, 2012

Layers of Imbrium floor excavated at Piton B

Southern contact of Piton B crater wall and rim. From LROC Narrow Angle Camera (NAC) observation M168203756R, orbit 9922, August 17, 2011; 290 meter-wide field of view captured from a mere 28.75 kilometers, resolution 42 centimeters per pixel, centered near 39.292°N, 359.883°E. North is up [NASA/GSFC/Arizona State University].
Hiroyuki Sato
LROC News System

Piton B is a young, fresh crater (about 4.5 km diameter) located in northeast Mare Imbrium. Along the upper part of this young crater wall, you can find clear layering similar as seen in Meteor Crater at east of Flagstaff, Arizona. The opening image highlights such layerings observed at the southern crater wall of Piton B.

In the lower right corner of this image is a portion of the crater rim, downslope is toward the top. The relatively resistant layers discontinuously outline their horizontal expanses. Among them, the blocky outcrop at the center of this image shows the clearest bedding plane. 

The thinnest layers are roughly 3 to 4 meters thick, assuming a slope angle about 30°.

Context for the Featured Image field of view (white rectangle) in the full width of the left and right frame of LROC NAC observation M168203756 [NASA/GSFC/Arizona State University].
Layer thickness estimates from orbital views are not as accurate as geologists would make standing on the outcrop, but many measurements at multiple craters give a great estimate of the general layer thicknesses of the original lava flows. Knowing thickness of flows helps us understand the viscosity and flow rates of ancient mare volcanism.

Piton B (below center) in LROC Wide Angle Camera 100 meter resolution mosaic on LOLA laser altimetry based topography from a simulated perspective 14 km over the vast Imbrium floor. Beyond are Piton A and their namesake Piton Mons [NASA/GSFC/Arizona State University].
Explore the fresh crater wall of Piton B in full NAC frame yourself, HERE.

Related Posts:

Tuesday, July 3, 2012

Craters near Lunokhod-1 officially named

Luna 17, the lander that carried Lunokhod 1 to the surface; debarking ramps for the rover visible extending down to the surface to the right. Many rover tracks are visible around the lander and throughout LROC Narrow Angle Camera (NAC) frame M175502049RE, LRO orbit 10998, November 9, 2011. View the original contextual image with enlarged inset, HERE [NASA/GSFC/Arizona State University].
Olga Zakutnyaya
The Voice of Russia
 

A number of moon craters in the vicinity of Lunokhod–1 lunar rover have been given their own names. They were named in honor of the crew members of the first self-propelled vehicle on the surface of the celestial body.

The experiment carried out more than 40 years ago is to be repeated in the course of “Luna-Resource” expedition which should be launched no earlier than 2015.

The International Astronomical Union has approved 12 new names for small craters on the Moon, and now they have names of the members of the first lunar expedition and scientists who were involved in the project. Despite the fact that these people were not able to walk on the Moon’s surface themselves, they were the ones who led Lunokhod–1 – the first planet rover on the surface of an alien celestial body. All craters are located in the area of the “Sea of Rain” (Mare Imbrium) where the landing vehicle of Luna-17 interplanetary automatic station soft-landed in November 1970. It delivered Lunokhod lunar rover onto the Moon’s surface. All craters are comparatively small, their diameter ranging from 100 to 400 meters.

Thus, the names of Albert, Borya, Gena (in honor of the navigator Gabdulkhai Latypov), Igor, Kolya, Kostya, Leonid, Nikolya, Slava, Valera, Vasya, and Vitya appeared on the Moon.

The Luna-17 spacecraft was built by the design and construction bureau of the machine-engineering plant named after S.A. Lavochkin (now NPO Lavochkin). Lunokhod-1 was equipped with a set of scientific devices to explore the lunar soil. In the course of 10 months that it was working on the Moon, the rover traveled over 10.5 kilometers and sent back to Earth information about the mineral composition and characteristics of the lunar surface.

Lunokhod 1 rover in its final parking place (38.315°N, 324.992°E) on the surface of Mare Imbrium. LROC Narrow Angle Camera (NAC) observation M175502049RE, orbit 10998, November 9, 2011, resolution 33 cm per pixel. View original Featured Image released March 14, 2012 (with enlarged inset) HERE. [NASA/GSFC/Arizona State University].
Lunokhod-1 was controlled remotely via the center for space communications by two crews – five people each who worked in shifts. Each crew consisted of a commander, a driver, a navigator, a flight engineer, and a high gain antenna operator. Thus there were 10 people all together, plus a reserve driver and reserve high gain antenna operator.

Even though by the time Lunokhod-1 was launched American astronauts had already landed on the Moon, the soviet rover was no less a remarkable scientific and technical achievement. Unfortunately, at that time, the meaning of this achievement was overshadowed by the defeat in the race to put a man on the moon. Lunokhod-1, with all its novelty and complexity, was more of a consolation prize. At least that was the general attitude – and analysts might object, of course. Sadly, it was what determined the further development of the lunar program. After the improved version Lunokhod-2 in 1973, there was Lunokhod-3 which never made it to the Moon. As a result, the Lunar Program of the USSR was suspended. Forty years on there has been little progress.

Today it can be said that it was a mistake. Weak consolation might be the fact that space programs in other countries primarily in the United States have also been suspended. However, the comparison might not be accurate – paradoxically as it may sound as though the soviet moon explorations at the end of the “manned moon race” were in a better state (if not financially from the strategic point of view). A continuation of manned expeditions demanded huge resources and clear goals, which probably did not exist at that time. Autonomous expeditions were easier from the point of view of their preparation but brought back much more scientific results. Besides, by that time, complicated initial stages with lots of failures were overcome and so reliability was higher.

Far western 1970 Landing Zone of the Soviet Union's Luna 17, and the final parking spot of the first remote-operated lunar rover, Lunokhod-1. The French-built laser reflector array deployed from the Lunokhod eluded detection for four decades until its precise location was reacquired by the LROC Narrow Angle Camera in 2009. It's relocation added vital precision to measurements of the Earth-Moon distance that may answer important questions in astrophysics. LROC Wide Angle Camera 100 meter Global Mosaic overlaid upon LOLA topography and assembled using the NASA LMMP ILIADS application [NASA/GSFC/LMMP/Arizona State University].
Something similar is happening to NASA’s Mars exploration program. A long and ongoing exploration of the planet with more and more sophisticated and complex tasks resulted in the fact that the US became a true leader in the Mars programs. That was, in fact, the main argument by scholars who objected to cuts in NASA’s planetary space budget in 2013. In their opinion to lose such an important scientific and technical foundation would be a poor strategic move.

The current plans of Russia in the area of space exploration include returning to the Moon with landing vehicles and a mini-rover – a self-propelled machine which is being developed by an Indian organization for the purposes of the Luna-Resource program. It is planned to repeat lunar soil collection considering previous experiences. If in the course of the first expeditions the soil was collected only in the places of landing – now the goal is to combine the operation of the mini-rover and returning spacecraft. The mini-rover is to determine the most interesting spots and collect soil from them and then the spacecraft should return the samples to the Earth.

New Names Approved for Twelve Small Lunar Craters - The Working Group for Planetary System Nomenclature has approved 12 new names for small craters on the Moon: Albert, Borya, Gena, Igor, Kolya, Kostya, Leonid, Nikolya, Slava, Valera, Vasya, and Vitya. For details, see the map of LAC 24 and the Lunokhod-1 traverse map in the Gazetteer of Planetary Nomenclature [USGS].
Yet as of now these are only plans. Information from the Moon is coming daily. NASA LRO and GRAIL spacecraft continue to work in the Moon’s orbit (two spacecraft which measure lunar gravity fields). Several days ago, the NASA LRO mission published recent images of the lava fields formed as a result of asteroid impacts. The images were taken by LROC – Lunar Reconnaissance Orbiter Camera. This camera is also connected to the Lunokhods – in 2010, the first high resolution images were printed and it was possible to see Lunokhod-1 and the landing spacecraft and the wheel tracks. Interesting that in the same year a group of American scientists announced that they had managed to intercept a pulse from a laser retroreflector on Lunokhod-1.

It is probable that these circumstances have raised the interest in the Lunokhod program again. Naturally, recognition of the achievements of the soviet scientists is satisfying on the one hand, but on the other the interest is mostly coming from western institutions and space lovers. Without the LROC images, the “favourite lunar tractor” would be remembered only by those who are truly loyal to space science. That is why one of the tasks of the future lunar program is not only to learn again how to land and control spacecraft on the Moon, but also how to inform people about it in plain language, and on a regular basis.

Related: Lunokhod-1 revisited (March 15, 2012)

Wednesday, April 11, 2012

LROC: Flow Boundary in Mare Imbrium

A small scarp is exposed in this high sunrise incidence angle (75.95°) Narrow Angle Camera frame, around 95 kilometers north by northeast of Mons La Hire in Mare Imbrium. The area to the east is raised relative to the area on the west of the scarp by as little as 10 meters. LROC NAC M177792062L, LRO orbit 11337, December 6, 2011; field of view 610 meters, resolution 0.6 meters per pixel from 43.86 kilometers. View the full-size LROC Featured Image HERE [NASA/GSFC/Arizona State University].
Drew Enns
LROC News System


Today's Featured Image shows the boundary of a flow front in Mare Imbrium. Unlike other flows LROC has observed (granular, impact melt), these are lava flows! The flows are about 35 m thick, making them hard to observe unless the Sun is low and casting long shadows.

Apollo 15 imaged the flows early in the lunar morning, when the Sun was low on the horizon to help the low relief flows cast larger shadows!

Combining the observed geometric properties of these flows with viscosities calculated from the Apollo samples allow scientists to constrain how lava behaves on the Moon.

The same field of view at a slightly less inclined morning incidence angle (60.84°), LROC NAC M129452673R, orbit 4211, May 25, 2010, resolution 0.46 meters from 37.66 kilometers [NASA/GSFC/Arizona State University].
For context, the full, uncorrected approximate 2200 meter width of the field of view swept up in LROC NAC M129452673R. The area of interest is just left of center [NASA/GSFC/Arizona State University].
LROC Wide Angle Camera (WAC) context for the LROC Featured Image, released April 11, 2012 and narrowly focused near 30.593° N, 335.302° E. The WAC observation above was swept up from the orbiter during the same orbital pass as that of the Featured Image NAC frame. The large incidence angle brings out subtle changes in topography, enhancing the Imbrium lava flows. Image field of view is 35 kilometers. LROC WAC M177791761C (604nm), resolution 60 meters per pixel [NASA/GSFC/Arizona State University].
The Imbrium flows are fairly thick, and the WAC context shows them extending for at least 120 km, but the flows continue for several hundred kilometers. Should we expect this? Because the Moon's gravity is weaker than the Earth's, we can expect lunar lava flows to be ~1.7 times as thick as a terrestrial flow of similar length! 

Flows of similar length on Earth have only been observed in flood basalts, which are large volumes of lava that were erupted quickly. 

This correlation indicates that the lunar lava flows must have erupted quickly as well. Even so, these flows are some of the few examples still visible on the Moon's surface, and it is unclear how their thickness and extent relate to the majority of volcanism that filled in the large basins resulting in the maria.

Check out more lava related feature posts below and explore the lava flows in the full LROC NAC Featured Image, HERE.

Related Posts:
Layers near Apollo 15 landing site
Layering in Euler Crater
Old Man River of Lava