Size Duel deck / Space
Callisto
Length: diameter
4,821 km (2,996 mi)
A heavily cratered moon of Jupiter, almost as wide as Mercury.
Sources and checks
Checked 2026-10-21: Researched by Codex (two independent publishers, verbatim quotes); every counted quote re-found on its page by the server check (content-verify); scope and plausibility reviewed by Claude (AI build agent). Quotes are short passages from each source.
“4,821 km”NASA: source, retrieved 2026-10-21; quote re-found by the server check
“Callisto (4821 km)”European Space Agency: source, retrieved 2026-10-21; quote re-found by the server check
“4821”Store norske leksikon: source, retrieved 2026-10-21; quote re-found by the server check
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