How do lunar orbiters like LRO image Apollo landing sites and what resolutions are available?
Executive summary
Lunar Reconnaissance Orbiter (LRO) images Apollo sites with the LROC narrow-angle camera (NAC) at pixel scales down to about 25 cm/pixel in low-altitude passes, and typical NAC images used for Apollo site work range from ~40 cm to ~1.4 m/pixel depending on orbit and campaign (examples: 25 cm best-case; M175428601 at 40 cm used for Apollo 12 visualization) [1] [2] [3]. LRO teams combine multiple NAC frames, stereo pairs and digital terrain models (DTMs) to reveal hardware, rover tracks and bootprints and to make 3‑D visualizations of the landing sites [2] [4].
1. How the orbiter sees the Apollo sites — a camera and an altitude story
LRO carries the Lunar Reconnaissance Orbiter Camera (LROC) suite: a pair of high-resolution narrow-angle cameras (NAC) and a lower-resolution wide-angle camera (WAC). The NAC produces the close-up images used to detect descent stages, rovers, experiment packages and even astronaut trails; the effective pixel scale you get from NAC is governed by the spacecraft altitude and imaging campaign, so when LRO was lowered to tens of kilometers it produced images as fine as ~0.25 m/pixel and during other periods produced images in the ~1.0–1.4 m/pixel band [1] [3] [5].
2. Best-case resolution and what that means on the ground
In dedicated low-altitude mapping periods, LROC NAC images have reached about 25 cm per pixel — the “best” resolution publicly emphasized by NASA — which is sufficient to resolve objects the size of lunar module descent stages, the lunar roving vehicles and clear astronaut bootprint trails when lighting is favorable [1] [6]. Other published NAC frames used for site visualizations are at roughly 40 cm/pixel (an NAC frame used for an Apollo 12 3‑D visualization is cited as 40 cm/pixel) [2]. When LRO is in higher or more elliptical orbits, NAC pixel scales increase to ~1.0–1.4 m/pixel [3].
3. Image processing: from single frames to stereo and DTMs
Scientists don’t rely on a single picture. LROC teams stitch mosaics, use stereo NAC pairs to build digital terrain models (DTMs) and combine imagery with other LRO instruments (e.g., LOLA or Mini-RF) to create 3‑D visualizations and flyovers of the landing sites. For Apollo 12, for example, the team used NAC imagery (40 cm/pixel) together with a stereo-derived DTM (2 m/pixel) to produce the 3‑D visualization [2] [7]. The featured-sites web tools let the public flip through images of different lighting, compare before/after shots and follow traverse maps built from many images [4].
4. What you can actually see on the surface
At tens of centimeters per pixel and with favorable sun angles, LROC images show lunar module descent stages, ALSEP instrument packages, lunar rovers and the astronauts’ traversal paths and bootprints; multiple mission pages highlight that hardware and tracks are clearly visible at Apollo sites [1] [8] [6]. NASA’s public visuals and the Planetary Society coverage repeatedly show that equipment and tracks are identifiable in NAC imagery and mosaics [8] [3].
5. Limits, caveats and how lighting and orbit affect detectability
Resolution is not the only limiter: sun angle, shadowing, surface slope and distance from nadir all change how features appear. LRO’s orbit has changed over the mission, so the “best” images came from specific low-orbit windows; the SVS page explicitly notes that the ~25 cm/pixel low-altitude images “will remain the best … until a future mission” because LRO later moved to a higher orbit [1]. Not found in current reporting: technical noise-floor numbers, modulation transfer function curves or exact orthorectification error budgets for every published frame — the sources summarize pixel scale and usage rather than exhaustive instrument performance tables [1] [2].
6. Competing perspectives and implicit agendas
NASA and LROC teams emphasize the ability to “revisit” and document human artifacts on the Moon and to support future landing-site selection — that framing underscores both heritage documentation and operational utility [1] [3]. Public-facing outlets (Planetary Society, SVS) highlight striking images and 3‑D visualizations to engage audiences; they draw attention to the best-resolution frames while noting the variability of orbit and lighting [4] [3]. Independent or skeptical readers should note those communications choices: NASA presents technical context but also packages images for public impact.
7. Bottom line for a user or researcher
If you need the sharpest orbital photos of Apollo sites, use LROC NAC low-altitude frames (best public cases ~0.25 m/pixel; commonly used frames ~0.4–1.4 m/pixel) and combine stereo-derived DTMs for 3‑D interpretation; public LROC featured-site pages and NASA SVS visualizations provide the primary image sets and metadata for these analyses [1] [2] [4]. Available sources do not mention third-party super-resolution claims beyond the LROC team’s published pixel scales and derived DTMs [1] [2].