Where the facts come from
Every factual claim on this site links to its source. This is the full list.
How we checked
Each fact was written alongside its source. Our build script stores the source text and, for every fact, checks that the key words and figures really appear in it. 123 of 123 checks passed when this site was last built (26 Oct 2026). Where we couldn’t find a NASA page that said it, we left the claim out.
The birthday Moon
The phase dates and times come from NASA Goddard’s tables of Moon phases for 1901 to 2100, by Fred Espenak, copied into this site by a script and checked against the published table. The table gives the four main phases in Universal Time; the in-between shape and “% lit” are worked out by us and are estimates.
Things that change
Moon exploration is busy again. Missions launch, land and end, and counts go up. Facts like these are marked “checked 26 Oct 2026” so you know how fresh they are. Fixed facts, such as the Apollo 11 landing in 1969, don’t change. Where NASA pages round a figure differently, we use NASA’s Moon facts page or the NASA Moon fact sheet.
All sources (28)
- NASA Goddard Space Flight Center: Phases of the Moon 1901 to 2100 (tables by Fred Espenak); used for the birthday Moon (5 facts)
- NASA NSSDC: Moon fact sheet (10 facts)
- NASA Science: Apollo 11 landing site, seen by LRO (1 fact)
- NASA Science: Earth and the Moon, by the numbers (2 facts)
- NASA Science: How the Moon formed (2 facts)
- NASA Science: Lunar Reconnaissance Orbiter (1 fact)
- NASA Science: Lunar eclipses (2 facts)
- NASA Science: Moon facts (34 facts)
- NASA Science: Moon missions (11 facts)
- NASA Science: Moon phases (6 facts)
- NASA Science: Moonlight (1 fact)
- NASA Science: Moonquakes (2 facts)
- NASA Science: Supermoons (2 facts)
- NASA Science: Tides (7 facts)
- NASA Science: Top Moon questions (10 facts)
- NASA Science: Water and ices on the Moon (1 fact)
- NASA Science: Weather on the Moon (1 fact)
- NASA Science: What the Moon is made of (2 facts)
- NASA Science: Who has walked on the Moon? (4 facts)
- NASA Space Place: All about the Moon (3 facts)
- NASA Space Place: How far away is the Moon? (1 fact)
- NASA Space Place: What are the Moon’s phases? (1 fact)
- NASA: Apollo 11 mission overview (4 facts)
- NASA: Apollo 15 (1 fact)
- NASA: Apollo 17 (1 fact)
- NASA: Apollo 8 (2 facts)
- NASA: Artemis II (1 fact)
- NASA: July 20, 1969, One Giant Leap for Mankind (5 facts)