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. 105 of 105 checks passed when this site was last built (25 Oct 2026). Where we couldn’t find a NASA or ESA page that said it, we left the claim out.
Things that change
Mars exploration moves on. Rovers set new records, missions launch and end, and new results are published. Facts like these are marked “checked 25 Oct 2026” so you know how fresh they are. Fixed facts, such as Mariner 4’s flyby in 1965, don’t change. Where NASA pages round a figure differently, we use NASA’s Mars facts page or the NASA Mars fact sheet.
All sources (26)
- ESA: Mars Express (2 facts)
- NASA GISS: Mars24 sunclock algorithm (1 fact)
- NASA JPL: Curiosity captures shining clouds (1 fact)
- NASA NSSDC: Mars fact sheet (14 facts)
- NASA Photojournal: Sunset in Mars’ Gale Crater (2 facts)
- NASA Science: Curiosity rover (2 facts)
- NASA Science: Deimos (1 fact)
- NASA Science: Face on Mars (1998 image) (1 fact)
- NASA Science: Ingenuity Mars Helicopter (2 facts)
- NASA Science: Mariner 4 (2 facts)
- NASA Science: Mars Pathfinder (4 facts)
- NASA Science: Mars Reconnaissance Orbiter (1 fact)
- NASA Science: Mars facts (38 facts)
- NASA Science: Mars moons (3 facts)
- NASA Science: Perseverance instruments (1 fact)
- NASA Science: Perseverance rover (4 facts)
- NASA Science: Perseverance rover components (4 facts)
- NASA Science: Phobos (3 facts)
- NASA Science: Spirit and Opportunity (3 facts)
- NASA Science: The “Face on Mars” (1 fact)
- NASA Science: Viking 1 (3 facts)
- NASA Science: Viking 2 (1 fact)
- NASA Space Place: All about Mars (5 facts)
- NASA Space Place: Curiosity (2 facts)
- NASA Space Place: The Mars rovers (1 fact)
- NASA: Humans to Mars (3 facts)