Locations of Anthropogenic Sites on the Moon R. V. Wagner1, M. S. Robinson1, E. J. Speyerer1, and J. B. Plescia2 1Lunar Reconnaissance Orbiter Camera, School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-3603; [email protected] 2The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723 Abstract #2259 Introduction Methods and Accuracy Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera To get the location of each object, we recorded its line and sample in (NAC) images, with resolutions from 0.25-1.5 m/pixel, allow the each image it appears in, and then used USGS ISIS routines to extract identifcation of historical and present-day landers and spacecraft impact latitude and longitude for each point. The true position is calculated to be sites. Repeat observations, along with recent improvements to the the average of the positions from individual images, excluding any extreme spacecraft position model [1] and the camera pointing model [2], allow the outliers. This process used Spacecraft Position Kernels improved by LOLA precise determination of coordinates for those sites. Accurate knowledge of cross-over analysis and the GRAIL gravity model, with an uncertainty of the coordinates of spacecraft and spacecraft impact craters is critical for ±10 meters [1], and a temperature-corrected camera pointing model [2]. placing scientifc and engineering observations into their proper geologic At sites with a retrorefector in the same image as other objects (Apollo and geophysical context as well as completing the historic record of past 11, 14, and 15; Luna 17), we can improve the accuracy signifcantly. Since trips to the Moon. the retrorefector positions are known to meter-level accuracy from Earth- To date, we have identifed almost all of the robotic soft landers that based laser ranging [5], we used ISIS routines to fx the retrorefector pixel landed successfully (Surveyor, Luna, Chang’e 3), including the rovers at its known coordinates before calculating the coordinates for other associated with three of them (Lunokhod 1 and 2, and Chang’e 3 Yutu). We objects. This reduced variance in the calculated hardware locations by a have not yet located the frst two successful lunar landers (Luna 9 and factor of 5. Luna 13, launched by the Soviet Union), which are very small relative to For the Chang’e 3 lander, cross-over corrected kernels are not currently the NAC pixel scale and have poorly-constrained landing coordinates. We available for images that contain the lander and rover, so we used post- have also identifed both GRAIL impact sites, four Ranger and four Apollo landing images to identify the landing position in pre-landing images, and Saturn-IVB impact sites. The locations of crewed Apollo Lunar Module derived the coordinates from the “prior” images. (LM) descent stages, Lunar Roving Vehicles (LRV), and science instruments were also identifed in NAC images. Historical Background Prior identifcations of anthropogenic targets were made from Apollo- era photography, radio tracking, and laser ranging. Historic coordinates for Left: Spread of projected locations many anthropogenic targets were summarized in [3] and were used as for each measured object at the starting points for locating the landing and impact sites in NAC images. Apollo 12 landing site. Each Davies and Colvin [4] refned estimates of Apollo equipment based on colored dot marks the location from laser ranging at three of the six landing sites, radio tracking of ALSEP radio one image; the yellow dots mark signals (interferometry) that gave the distances between the ALSEP central the average locations. Above: Spread of projected stations, and photogrammetry of surface photos to derive the relative and locations for the Luna 17 lander, absolute positions of the LMs and other equipment. Our coordinates are after calibrating with the consistent with those of Davies and Colvin, while refning the accuracy and Map of the locations of all of the anthropogenic features located in this work. Orange indicates retrorefector mounted on the including non-Apollo sites. impactors, blue indicates unmanned landers, and green indicates Apollo landing sites. Lunokhod 1 rover 2.3 km north. Scale matches in both fgures. Impacts Robotic Landers Apollo Landings Ranger Program: The United States' Ranger spacecraft (1961- Surveyor Program: From 1966 to 1968, the United States The United States' Apollo landings (1969- 1965) were designed to image portions of the Moon at high launched seven Surveyor robotic landers as a precursor to 1972) were the frst, and so far only, crewed resolution, which they accomplished by entering a decaying the Apollo manned landings. Five of them landed success- missions to the Moon. At the six landing orbit, and imaging until they hit the surface. This resulted fully, and one, Surveyor 3, was later visited by Apollo astronauts. sites, we recorded the positions of the in spectacular images, as well as spectacular craters. following features: Luna Program: The Soviet Union launched a number of lunar Apollo SIV-Bs: On each of the United States' Apollo missions missions from 1958 to 1976, eight of which were landers that LM: The descent stage of the Landing (1969-1972), the Saturn IV-B booster was used to leave made it to the surface in one piece (although the Luna 23 Module. Earth orbit. On Apollos 13 through 17, the SIV-B was later sample return mission fell over on landing). Two of them ALSEP: The central station of the Apollo maneuvered to impact the Moon, providing a strong signal Luna 17 and 21, carried Lunokhod rovers, both of which Lunar Surface Experiment Package, which for the Apollo seismic network. traversed several kilometers over a few months. handled communication and power distribution for the experiments the GRAIL: The GRAIL mission (2011-2012) consisted of two Chang'e 3: In December 2013, China launched the astronauts left on the surface. orbiters, Ebb and Flow, which mapped the Moon's gravity frst lunar lander in 37 years, which successfully LRRR: Laser Ranging RetroRefector. feld in unprecedented detail. After a successful mission, landed and deployed a small rover, named Yutu. See PSE: Passive Seismic Experiment. Apollo 11 they were commanded to crash into the surface. LROC was poster #304 (abstract #1859) for more about LROC only left an LRRR and seismometer on the able to acquire images of the impact site both before and imaging of Chang’e 3. surface, so the seismometer package housed after the impact, allowing us to locate the 5 meter craters. Calculated Location Standard Deviation (m) Total Spread (m) its own power and communication systems. Lat Lon Radius (m) Lat Lon Lat Lon Images LRV: The fnal parking spots of the Lunar Calculated Location Standard Deviation (m) Total Spread (m) Surveyor 1 -2.4745 316.6602 1,735,511d 6.9 4.8 17.5 13.6 7 Roving Vehicles, on Apollos 15, 16, and 17. Lat Lon Radius (m) Lat Lon Lat Lon Images Surveyor 3 -3.0162 336.5820 1,735,967b 7.2 4.1 40.3 23.4 40 Ranger 6 9.3866 21.4806 1,735,409b 5.7 3.0 16.1 10.6 8 Surveyor 5 1.4550 23.1944 1,735,348d 12.6 4.2 27.8 10.6 5 Ranger 7 -10.6340 339.3229 1,735,609d 6.3 2.9 21.7 7.9 8 Surveyor 6 0.4743 358.5725 1,736,643d 5.5 2.6 13.8 6.9 5 Ranger 8 2.6377 24.7881 1,735,235d 7.9 4.9 25.1 15.2 8 Surveyor 7 -40.9811 348.4873 1,737,481d 3.3 7.9 11.4 30.6 11 Ranger 9 -12.8281 357.6116 1,735,878b 5.2 2.9 15.0 9.9 8 Luna 16 -0.5137 56.3638 1,734,948b 6.1 2.1 19.9 8.0 16 b A13 SIVB -2.5550 332.1126 1,736,244 10.0 4.4 28.2 14.5 11 Luna 17a 38.23763 324.99847 1,734,929b 1.3 1.3 7.0 5.8 29 d A14 SIVB -8.1810 333.9695 1,735,615 7.5 5.2 26.5 18.0 10 Lunokhod 1e 38.3151 324.9919 1,734,929c 9.8 5.9 46.2 23.7 29 A15 SIVB -1.2896 348.1755 1,736,301b 4.4 4.6 15.1 15.3 20 Luna 20 3.7863 56.6242 1,735,620b 8.1 2.7 27.2 9.2 16 A17 SIVB -4.1681 347.6693 1,736,231b 10.1 1.9 35.4 6.1 12 Luna 21 25.9993 30.4077 1,734,720b 13.2 7.9 41.1 21.4 8 Calculated Location Standard Deviation (m) Total Spread (m) GRAIL-A 75.6083 333.4043 1,738,169d 5.1 3.2 15.1 9.0 10 e c Lat Lon Radius (m) Lat Lon Lat Lon Images d Lunokhod 2 25.8323 30.9221 1,734,639 12.0 5.2 48.9 17.0 14 GRAIL-B 75.6504 333.1643 1,738,451 4.6 3.6 14.3 11.5 9 a b Luna 23 12.6669 62.1511 1,733,732b 8.5 2.5 29.5 10.8 26 A11 LM 0.67415 23.47315 1,735,474 0.5 1.2 2.6 7.3 47 a b Table footnotes: aCoordinates adjusted for retrorefector locations. bElevation from NAC Luna 24 12.7145 62.2129 1,733,730b 8.8 2.7 30.2 13.3 24 A11 PSE 0.67321 23.47315 1,735,472 0.7 1.2 4.2 6.9 46 c d e A12 LM -3.0128 336.5781 1,735,978b 6.3 3.5 27.4 15.7 43 DTM.