Surveyor Crater: Before and After

Another look at Surveyor Crater, the Apollo 12 and Surveyor 3 landing site, under early morning illumination not much above the horizon from what Conrad & Bean encountered after the second manned landing on the Moon in November 1969. (View the labeled LROC Featured Image release HERE,, and read a description for comparisons made between a high-resolution Lunar Orbiter photograph of the same area. Field of view above is 270 meters at this, the full 47 centimeter per pixel resolution; cropped from LROC Narrow Angle Camera (NAC) mosaic M177785917RL, orbit 11336, December 6, 2011; 73.1° angle of incidence from 38.15 kilometers [NASA/GSFC/Arizona State University].

Ryan Clegg
LROC News System

The Lunar Orbiter program, much like LRO, was designed primarily to obtain images to allow scientists and engineers to characterize the lunar surface in the context of finding safe and engaging landing sites for future missions.

A total of 5 Lunar Orbiters (LO) were sent to the Moon, and they collectively photographed most of the lunar surface at 60 to 600 meters resolution, with resolutions as high as 1 meter per pixel for some of the LO-5 photographs.

In 1967, NASA launched Lunar Orbiter 3 with the primary objective of finding safe landing sites for the Surveyor and Apollo missions. Both a Surveyor and an Apollo mission soon visited one area that the Lunar Orbiter photographed. Surveyor 3 landed on April 20, 1967 in Oceanus Procellarum at approximately 3.02°S, 23.42°W.

The spacecraft landed in a small, 200 m crater that was later named Surveyor Crater.

Recovered from the original telemetry tapes by the Lunar Orbiter Image Restoration Project (LOIRP). LO3-154 H2 was recently released, including an inset marking the Surveyor 3 and Apollo 12 expeditions [LOIRP/Moonviews.com].

LROC image M1108432631R (left, incidence angle = 68.8 degrees) and Lunar Orbiter 3 image LO3-154-H2 (right, incidence angle = 67.2 degrees) of Surveyor Crater, the eventual landing site of both Surveyor 3 and Apollo 12. Both images were taken at similar illumination geometries and the NAC image has been stretched to match the saturation seen in the LO-3 image [NASA/GSFC/USGS/LPI].

The LROC NAC mosaic (bottom) and an similarly arranged field of view from Lunar Orbiter image 3154-H2 (top, incidence angle = 67.2°) of Surveyor Crater, eventual landing site of Surveyor 3 and Apollo 12 soon after.

Two and a half years later, on 19 November 1969, Apollo 12 demonstrated the Lunar Module's capability to make a pinpoint landing by setting down on the edge of Surveyor Crater, about 155 m from the deactivated Surveyor 3 spacecraft. Almost 45 years later, LROC imaged the same area of Oceanus Procellarum that LO-3 photographed. The LROC image, however, reveals some new features - the Apollo 12 Lunar Module (LM), Surveyor 3 spacecraft, and astronaut tracks are all visible. Perhaps most evident is that Surveyor Crater and the area around the LM are noticeably brighter than in the LO image.

Apollo 12 cmdr. Pete Conrad poses by the Surveyor 3 unmanned spacecraft two and a half years after the small vehicle soft landed just inside the east rim of a 200 meter crater in Oceanus Procellarum, a deliberate test and demonstration of rapid advancements in precise landing navigation necessary for future landings. Conrad holds up the sampling arm and grasps the video camera assembly, both retrieved and providing valuable study of the effects of the dusty landing plume originating from Intrepid lunar module. Alan Bean snapped this picture. [NASA/ALSJ].

This increase in reflectivity resulted from effects of the rocket exhaust interacting with the regolith during the descent of the Apollo 12 Lunar Module. Directly beneath and adjacent to the LM the surface appears darker because the exhaust gas disrupted and roughed up the surface. However, a few meters away from the lander and extending outward for several hundred meters, the surface was altered in such a way as to make it more reflective, possibly a result of smoothing.

During the Apollo 12 descent, Pete Conrad flew the spacecraft around the edge of Surveyor Crater in order to get to the safe landing spot he wanted. The crater then likely acted as a mechanism to contain the rocket exhaust, causing the entire crater to experience disturbance and appear more reflective.

A pixel, and part of another (marked by the arrow) just barely shows the Apollo 12 lunar module descent stage profile, on the "shoulder" of "The Snowman" crater group, from 106.48 kilometers above a point on the lunar surface well to the east. The original resolution above 3.5 meters per pixel, May 31, 2012. LROC NAC frame M193067752R. (The long shadow of the mast of Surveyor 3 may just be visible as a small bump on the shadow line across the interior of Surveyor crater [NASA/GSFC/Arizona State University].

The full-width of LROC NAC frame from M193067752R, where a rectangle marks the field of view at 40% full resolution in the image immediately above, camera and spacecraft were slewed 60° off nadir, providing an unusual oblique observation. (Both this image abd the one referenced immediately above it originally used to illustrate the post "Apollo 12 at 43 Years," Nov. 20, 2012) [NASA/GSFC/Arizona State University].

LROC WAC context mosaic, with the location of Surveyor crater marked. Note proximity with the ejecta rays far-flung south-southwest from Copernicus, beyond the frame at upper right). Cropped from the LROC QuickMap application, set at 125 meters resolution [NASA/GSFC/Arizona State University].

Be sure to explore the entire NAC frame (M177785917L and M177785917R mosaic), HERE.

Previous Posts:
Apollo 12 at 43 Years (November 20, 2012)
Pinpoint Landing on the Moon (Apollo 12) (March 12, 2012)
New Views of Apollo 12 (September 8, 2011)
First Low Altitude Apollo 12 NAC Image (August 11, 2011)
Triumph (and disappointment) of Apollo 12 (November 19, 2009)
Apollo 12 Second Look:Midday on the Ocean of Storms (November 4, 2009)
First Look: Apollo 12 and Surveyor 3 (September 3, 2008)

LROC: America's last unmanned lunar lander

Surveyor 7, on the ejecta blanket of Tycho, the last of the Surveyor spacecraft (1967-1968), and the only one of the series to land in the lunar highlands. LROC Narrow Angle Camera NAC frame M175355093L, LRO orbit 10976, November 8, 2011; field of view is 500 meters across, viewed at the original scaled 43 cm per pixel resolution at an illumination incidence angle of 56.22° Inset, from the LROC Featured Image released September 7, 2012, is enlarged 4x [NASA/GSFC/Arizona State University].

Ryan Clegg
LROC News System

Surveyor 7 landed in the lunar highlands (40.980°S, 348.486°E) on 10 January 1968, on an impact-melt coated ejecta blanket 46.6 km (29 miles) north of the rim of Tycho Crater. The last spacecraft of the Surveyor series, it was sent to an area far from the mare in the southern highlands, in order to sample and analyze materials different from those of the other Surveyor missions. Surveyor 7 was the only Surveyor spacecraft to be sent to a region solely for scientific interest, rather than to obtain more data for the upcoming Apollo program, since program managers had decided that the previous Surveyor missions had already provided sufficient data to enable a safe Apollo landing. Results from the spacecraft’s alpha scattering detector showed that the highland crust is poorer in iron than the maria analyzed by the other Surveyors.

Landing site of Surveyor 7 captured at a higher angle of incidence (83.96°) and altitude (44.94 km),  in context with the prominent impact melt pond to the northeast, its intended landing site. LROC NAC observation M131724362L, spacecraft orbit 4545, June 21, 2010; resolution 50 cm [NASA/GSFC/Arizona State University].

Panorama of the Surveyor 7 landing site, taken by Surveyor 7 [NSSDC].

A total of 21,091 pictures were transmitted to Earth by Surveyor 7. One of the most stunning image sets is a photomosaic panorama of the landing site, which shows the rim of the 82-km diameter Tycho Crater on the horizon. On the surface of the Moon, as on Earth and elsewhere, impact craters are typically hidden from sight until you are standing right up on the rim. The Apollo 14 astronauts encountered this problem as well, when taking samples during a radial traverse of Cone crater. They lost sight of the crater rim during their traverse and eventually had to turn back before catching a glimpse of the interior of the crater in order to save enough oxygen for the journey back to the Lunar Module. LROC images (February 4, 2011, August 19, 2009) later confirmed that the crew came within 30 yards of the crater rim.

Surveyor 7 could only just make out the rim of Tycho Crater from its landing site. However, from an orbit of 50 km above the surface the panoramic view of the stunningly well preserved impact crater and its majestic central peaks is spectacular.

Simulated view from several kilometers above a point north of the Surveyor 7 (blue square) shows it's proximity with Tycho [NASA/LMMP/GSFC/Arizona State University].

The Surveyor missions not only provided critical engineering data that helped enable the safe Apollo landings that followed, but also showed that powered descent to the lunar surface was feasible and straightforward. Robotic precursor missions (such as automated sample return missions and in-situ resource utilization demonstrations) will undoubtedly play a similarly important role as we prepare for the seventh human lunar landing and beyond.

Be sure to explore the entire NAC frame (M175355093L) HERE. covering the Surveyor 7 site, and check out the central peaks of Tycho in the June 29, 2011 and May 21, 2012 Featured Images.

WAC context image of Tycho and the Surveyor 7 landing site [NASA/GSFC/Arizona State University].

Previous Posts Related to Surveyor 7:
LROC: Giant flow of Tycho impact melt (August 14, 2012)
Polygonal fractures on Tycho ejecta (June 15, 2011)
Surveyor 7 (February 12, 2011)
Surveyor 7: Our fragile lunar LDEF (October 27, 2010)
LOLA's Tycho and the Apollo era (March 28, 2010)

Related LROC Posts:
New View of Apollo 14
Trail of Discovery at Fra Mauro
Tycho Central Peak Spectacular!
View From The Other Side
Surveyor 1
Surveyor 3 and Apollo 12
Surveyor 5
Surveyor 6