Mapping the Moon’s minerals and caves (physically)

• 1969–72 · Apollo 11–17

  382 kg of rock and soil from six nearside sites.

• Apollo result

  Highlands are anorthosite (calcium-rich plagioclase); maria are basalt (pyroxene, plagioclase, olivine, ilmenite). This is the evidence for a global magma ocean.

• Apollo result

  Three minerals first described from lunar samples: armalcolite, tranquillityite, pyroxferroite.

• Apollo result

  KREEP identified: material rich in potassium, rare-earth elements and phosphorus, the last liquid of the magma ocean.

• 1970–76 · Luna 16, 20, 24

  About 300 g returned robotically from three eastern nearside sites.

• 2020 · Chang'e-5

  1,731 g from Oceanus Procellarum. Basalts dated to about 2.0 billion years, the youngest returned so far.

• 2022 · Chang'e-5

  Changesite-(Y), a new phosphate mineral, approved as the sixth mineral discovered on the Moon.

• 2024 · Chang'e-6

  1,935.3 g from the South Pole–Aitken basin: the first samples from the farside. Source

• 2024–25 · Chang'e-6

  Farside volcanism dated at 4.2 and 2.8 billion years; basalt source mantle holds 1–1.5 µg/g water, drier than the nearside. Source

• 1960s–70s · Telescopes

  Visible and near-infrared reflectance spectra separate high-titanium from low-titanium maria before any global orbiter.

• 1971–72 · Apollo 15, 16

  Orbital X-ray and gamma-ray spectrometers map Al/Si, Mg/Si and thorium along the equatorial ground tracks.

• 1990, 1992 · Galileo

  Multispectral flyby images show the South Pole–Aitken basin as an iron-rich anomaly on the farside.

• 1994 · Clementine

  First global multispectral map: 11 bands from ultraviolet to near-infrared at 100–200 m per pixel. First global iron and titanium oxide maps.

• 1998–99 · Lunar Prospector

  Gamma-ray spectrometer maps thorium, potassium and iron globally. Thorium concentrates in one nearside region, the Procellarum KREEP Terrane.

• 2003–06 · SMART-1

  Compact X-ray spectrometer D-CIXS measures Mg, Al, Si, Ca and Fe during solar flares.

• 2007–09 · Kaguya

  Multiband Imager and Spectral Profiler find pure anorthosite (over 98% plagioclase) in crater central peaks across the highlands.

• 2007–09 · Kaguya

  Olivine-rich exposures located around large impact basins; gamma-ray spectrometer produces the first global uranium map.

• 2007–09 · Chang'e-1

  First microwave radiometer in lunar orbit; brightness temperatures used to estimate regolith thickness and the helium-3 inventory.

• 2008–09 · Chandrayaan-1 M³

  Moon Mineralogy Mapper: 85 bands, 0.43–3.0 µm, 140 m per pixel, near-global. The reference mineral map still in use.

• 2011 · M³ result

  New rock type identified from orbit: magnesium-spinel anorthosite, never found in the sample collection.

• 2009– · LRO Diviner

  Thermal infrared maps silicate composition. Silica-rich, granite-like volcanic domes confirmed at Gruithuisen and Compton–Belkovich.

• 2009– · LROC WAC

  Seven-band camera (321–689 nm) yields a titanium dioxide map of the maria at about 400 m per pixel.

• 2019– · Chandrayaan-2

  CLASS X-ray spectrometer produces the first global sodium map; IIRS extends spectra to 5 µm.

• 2022– · Danuri

  Korean orbiter carries a gamma-ray spectrometer and ShadowCam, which images inside permanently shadowed craters.

• 1967–68 · Surveyor 5, 6, 7

  Alpha-scattering instruments make the first chemical analyses on the Moon: maria are basaltic, highlands aluminium-rich.

• 1970–73 · Lunokhod 1, 2

  Rover-mounted X-ray fluorescence spectrometers measure soil chemistry along the traverses.

• 2013 · Chang'e-3

  Yutu rover (X-ray and infrared spectrometers) finds a young basalt type in Mare Imbrium unlike any returned sample.

• 2019– · Chang'e-4

  Yutu-2, first rover on the farside, detects olivine and low-calcium pyroxene in Von Kármán crater, possibly excavated from the mantle.

• 2023 · Chandrayaan-3

  Pragyan rover at 69° S: laser spectrometer confirms sulfur in situ, with Al, Ca, Fe, Cr, Ti, Mn, Si and O. Source

• 1994 · Clementine

  Bistatic radar experiment suggests ice near the south pole. Result contested.

• 1998 · Lunar Prospector

  Neutron spectrometer detects excess hydrogen at both poles.

• 1999 · Lunar Prospector

  Deliberate crash into a south-polar crater. No water detected in the plume.

• 2009 · M³, Cassini, Deep Impact

  Three spacecraft see the 2.8–3.0 µm absorption of OH / H₂O across the sunlit surface, strongest at high latitude.

• 2009 · LCROSS

  Impactor strikes the permanently shadowed crater Cabeus. Ejecta contain 5.6 ± 2.9% water by mass, plus CO, H₂S, NH₃ and mercury. Source

• 2009– · Mini-SAR, Mini-RF

  Radar finds polar craters with ice-like polarisation. Rough rock gives the same signal; ambiguous.

• 2018 · M³ reanalysis

  First direct detection of surface ice: near-infrared ice absorptions in permanently shadowed craters within 20° of both poles, in about 3.5% of cold traps. Source

• 2020 · SOFIA

  Airborne telescope detects molecular H₂O at 6 µm in sunlit soil at Clavius: 100–412 ppm. Source

• 2023 · Chang'e-5 samples

  Impact glass beads in the soil hold solar-wind-derived water.

• 2022–23 · LunaH-Map, Lunar Flashlight

  Two NASA cubesats built to map polar hydrogen and ice. Failed · propulsion faults, neither reached lunar orbit.

• 2025 · PRIME-1 on IM-2

  First ice-drilling attempt. Lander came to rest on its side on 6 March; the drill moved through its full range but never reached soil. Not achieved Source

• 2025 · Lunar Trailblazer

  Orbiter built to map the form and abundance of water. Contact lost a day after launch; mission ended 31 July 2025. Lost

• 1966–67 · Lunar Orbiter

  Photographs of sinuous rilles lead to the hypothesis that they are lava channels and collapsed lava tubes.

• 1971 · Apollo 15

  Astronauts reach the edge of Hadley Rille, about 1.5 km wide and 300 m deep, and photograph layered basalt in its wall.

• 2009 · Kaguya

  Terrain Camera finds the Marius Hills Hole, the first known skylight: a vertical pit about 65 m across in a rille.

• 2009–10 · Kaguya

  Two more pits found, in Mare Tranquillitatis and Mare Ingenii. Source

• 2010–12 · LROC NAC

  0.5 m per pixel images taken at an angle show layered walls and floors that continue under the rim: overhangs of 20 m and more.

• 2014 · LROC NAC

  Automated search of the image archive finds over 200 pits. Most are in impact-melt ponds; under ten are in mare lava.

• 2021 · LROC

  Lunar Pit Atlas published: 281 pits with position, size and depth. Source

• 2017 · GRAIL

  Gravity gradients show long, narrow mass deficits under the maria, consistent with buried empty tubes over 1 km wide. Source

• 2017 · Kaguya radar

  Lunar Radar Sounder records a double echo (roof, then floor) near the Marius Hills Hole, matching a GRAIL mass deficit. Indicated tube length: tens of kilometres. Source

• 2017 · Modelling

  Structural analysis: in lunar gravity a lava tube could stay standing at widths of kilometres.

• 2022 · LRO Diviner

  Shaded floor of the Mare Tranquillitatis pit holds near 17 °C through the lunar day. Open surface swings from 127 °C to −173 °C. Source

• 2024 · LRO Mini-RF

  Reanalysis of 2010 radar images: a conduit leaves the Mare Tranquillitatis pit at 130–170 m depth, 30–80 m long and about 45 m wide. First radar evidence of an accessible cave. Source

• 2025 · Machine learning

  Deep-learning search of orbital images reports new candidate cave entrances beyond the atlas. Source

• Status

  No spacecraft has entered a lunar cave or imaged one from inside. Every tube detection is indirect. Unconfirmed

Dimensions from LROC shadow measurements; published values differ by source and lighting.

• GIMLI · NASA

  Ground-penetrating radar, seismometers and a gravimeter on a commercial lander and rover at the Marius Hills pit, to settle whether it opens into a tube. No launch date. Selected Sep 2026 Source

• VIPER · NASA

  Ice-prospecting rover with a 1 m drill for the south pole. Cancelled July 2024; reassigned to a Blue Origin lander. Late 2027 Source

• Chang'e-7 · CNSA

  Orbiter, lander, rover and a hopper carrying a water analyser into a shadowed crater near Shackleton. August 2026 launch called off. Delayed to 2027 Source

• LunarLeaper · ESA candidate

  Legged robot of about 15 kg with radar and gravimeter, to walk the ground above the Marius Hills tube. Not yet selected Source

• Moon Diver, Daedalus

  Earlier concepts to lower a tethered rover (NASA JPL) or an instrumented sphere (ESA study) into a pit. Not funded

• Caves

  LROC · mare pit craters · LROC · lunar atlases · JAXA · Kaguya radar, Marius Hills · Chappaz 2017 · GRAIL · NASA · Diviner pit temperatures · Carrer 2024 · Nature Astronomy · Eos · lava tube beneath pit · PSI · GIMLI · LunarLeaper · Acta Astronautica 2026

• Minerals and water

  CAS · Chang'e-6 results · Chang'e-6 mantle water · Chandrayaan-3 sulfur · Li 2018 · surface ice · SOFIA · molecular water · LCROSS · IM-2 / PRIME-1 · NASA · VIPER · SpaceNews · Chang'e-7 delay

• Literature, no link

  Entries without a source link rest on the published record: Pieters 2009 and Colaprete 2010 (Science), Ohtake 2009 (Nature), Haruyama 2009 (GRL), Robinson 2012 (PSS), Wagner & Robinson 2014 (Icarus), Lawrence 1998 and Feldman 1998 (Science), Sato 2017 (Icarus).

• Images

  NASA, NASA/JPL, NASA/GSFC/Arizona State University, ISRO/NASA/JPL-Caltech/Brown University/USGS. Public domain, retrieved from Wikimedia Commons.