Methodology

How every fact on this site is compiled, labeled, and kept honest.

Evidence labels

Important statements carry one of six standardized labels:

• Confirmed: directly measured or established beyond serious scientific dispute (Europa exists; the CMB is real).
• Strong Evidence: multiple independent lines point the same way, short of direct proof (Europa’s subsurface ocean).
• Estimated: a measured quantity with meaningful uncertainty; we state ranges where sources disagree (Betelgeuse’s distance).
• Hypothesis: a specific, testable scientific idea not yet settled (Pluto’s ocean; Mars methane sources).
• Theoretical: follows from accepted physics but unobserved (Hawking radiation, wormholes).
• Speculative: interesting ideas beyond current testability (multiverse variants, exotic life). Clearly fenced off.

Numbers

Physical values follow NASA planetary fact sheets, mission pages, and the cited literature; each object page lists its sources, and individual facts carry their own source where it differs. Missing values display as “not measured”: the Atlas never fills a gap with a guess. Big numbers are always translated into human comparisons, and we avoid scientific notation in reader-facing text.

Computed sky data

Tonight’s Sky is computed on our servers: Moon phase from the mean synodic cycle (accurate to a few hours) and planet visibility from the JPL approximate Keplerian elements (valid 1800–2050, arcminute-class accuracy). This is visibility guidance, not a precision ephemeris; exact rise/set times depend on your location. Eclipse dates follow the NASA eclipse catalog.

Live datasets

Exoplanets: the NASA Exoplanet Archive composite-parameters table, re-synced weekly. Values are the archive’s adopted estimates and revise over time. Launches: The Space Devs Launch Library 2, cached daily; windows shift constantly and every time is “no earlier than”.

AI assistance

Parts of this site’s content and data compilation are produced with AI-assisted research, then reviewed against the cited sources. Two features are AI-generated at runtime and labeled as such: the in-house “Sky notes” (written daily from our own computed data, never from scraped text) and “Ask the Atlas” answers (generated only from our cached data, instructed to admit ignorance). Translations of the interface are machine-generated; scientific content and legal text remain English-first.

Corrections

Astronomy revises itself; so do we. If you find an error, use the contact form. Substantiated corrections are applied to the page itself, not argued with.