iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Lunar pits are steep-walled depressions or openings in the Moon’s surface. Some expose overhangs or subsurface voids, and radar analysis indicates that a conduit extends at least more than 200 feet from the base of the Mare Tranquillitatis pit. That is evidence that some lunar pits may lead to caves—not proof that every pit does, or that a vast cave network has been mapped.
What is a lunar pit?
A lunar pit is a depression or opening with steep walls. When a pit exposes an underground void, it may also be described as a skylight: an opening through which a subsurface feature is visible. NASA’s 2014 account reported more than 200 pits, with diameters ranging from about 5 meters to more than 900 meters. Those numbers describe NASA’s inventory at the time, not a current total. The reported pits occur in lunar maria, impact-melt settings and highlands. NASA’s 2014 overview of lunar pits
How might lunar pits connect to caves?
One plausible explanation for some pits is the collapse of a roof above an underground cavity. In a volcanic setting, lava can flow beneath a hardened surface crust. If the lava drains away, it can leave a hollow tube; a collapse in its roof may expose the space below as a pit or skylight. NASA also discusses possible voids associated with impact-melt ponds. A pit’s surface appearance alone does not reliably reveal how it formed, so lava tubes are a leading explanation for some features, not a settled origin for every pit. NASA’s formation discussion
What evidence points to caves beneath the Moon?
Radar beneath Mare Tranquillitatis
The strongest named evidence comes from the Mare Tranquillitatis pit. A research team reanalyzed Mini-RF radar data collected by NASA’s Lunar Reconnaissance Orbiter (LRO) in 2010. NASA’s July 18, 2024 summary of the analysis reported evidence of a cave conduit extending more than 200 feet from the pit’s base. The full extent is unknown; it may continue farther beneath the mare. The result supports a subsurface conduit at this site, but it does not provide a complete cave map or establish that other pits connect to caves. Nature Astronomy study; NASA’s summary of the 2024 radar analysis
#1 Best Overall
Visible overhangs and voids
NASA’s 2022 account described two prominent pits with overhangs that clearly lead to caves or voids, and strong evidence for a possible large cave at another. Visible openings show that subsurface spaces exist at some sites, but an image of an opening does not establish the full dimensions or layout of a cave. NASA’s 2022 account of lunar pits and caves
Temperatures in shaded reaches
LRO Diviner observations and computer modeling indicated that permanently shaded reaches of some pits remain around 17 °C. This finding applies to the shaded locations considered, not to every pit or the whole environment inside an underground cave. It is evidence about thermal conditions in some locations, not a confirmation that caves are suitable for human habitation. NASA’s thermal findings
Rank #2
What the evidence does—and does not—show
- Established: The Moon has many reported pits, and observations show that some openings expose overhangs or subsurface voids.
- Supported at a named site: Radar analysis indicates a conduit extending more than 200 feet from the base of the Mare Tranquillitatis pit.
- Still unknown: The full extent and dimensions of that conduit, and whether other pits connect to caves.
- Not established: A complete map of lunar caves, direct human exploration of them, or their habitability.
Are lunar pits likely to be lava-tube entrances?
Some may be, but the evidence does not justify treating every lunar pit as a lava-tube entrance. In NASA’s 2022 account, UCLA doctoral student Tyler Horvath estimated that “About 16 of the more than 200 pits are probably collapsed lava tubes.” That is Horvath’s estimate as reported by NASA, not a claim that all pits—or even all pits with visible openings—have the same origin. NASA’s 2022 account
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesQuick Recap
Best Value
Rank #4
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
