About SkyDeck
SkyDeck is a small, independent astronomy site for people who look up from their backyard and want to know exactly what they are seeing. We publish one thing above all: the monthly "what's up" guide — a computed moon-phase calendar, meteor shower peaks taken from the International Meteor Organization's calendar, and planet visibility highlights from published ephemeris sources. Around that core we write evergreen explainers: moon names, dark-sky scales, lunar photography, and honest debunking where the folklore outruns the physics.
How we make the numbers
Moon phase times on SkyDeck are not scraped from other sites. They are computed in the browser by
our own implementation of the public-domain algorithms in Jean Meeus's Astronomical Algorithms
(chapter 49), converted to UT with the Espenak–Meeus ΔT polynomial. That engine is validated in
tests.mjs against the US Naval Observatory's published Dates of Primary Phases of the
Moon — all 25 primary phases from October 2026 through March 2027 matched within 2 minutes — and
cross-checked against timeanddate.com. The full validation table is published on the
calculator page and in the site README.
Editorial standard
Every dated claim on SkyDeck carries a "Verified:" date and a source link. Meteor shower peaks, radiants and ZHRs come from IMO calendars; planet events from In-The-Sky.org and published almanac tables; moon names from the Old Farmer's Almanac; the Bortle scale from Sky & Telescope's publication of Bortle's criteria. If we cannot verify a date, we do not print it. If a claim is folklore rather than astronomy — full moon names, blue moons — we say so plainly. Spotted an error? Please write to us; corrections are published, not quietly patched.