About Pluto Garden

Last updated 26 October 2026

Pluto Garden draws a birth chart as the real sky at the moment someone was born: Earth in the middle, and the Sun, Moon and every planet in its true direction and distance, in 3D. The traditional chart wheel and every placement by sign, degree and house sit underneath. It started as a small project shared with friends and is run independently. Drawing a chart is free and needs no account.

How the charts are calculated

Planet positions come from DE440, the planetary ephemeris NASA’s Jet Propulsion Laboratory publishes for astronomers and spacecraft navigation. Our own engine turns it into the apparent positions astrologers use, with the same astronomical models as the Swiss Ephemeris (light-time, aberration, precession and nutation). It agrees with the Swiss Ephemeris to a small fraction of an arcsecond and is tested against JPL’s own reference positions.

• The zodiac is tropical, as in most Western astrology.
• Houses are Placidus by default (whole sign is a setting). Inside the polar circles, where Placidus can’t be drawn, Porphyry is used.
• The North Node and Black Moon Lilith are the mean points.
• The time zone, including historical daylight saving time, is worked out from the birthplace’s coordinates, never from a typed offset. Very old charts whose local time can’t be pinned down are flagged on the page.
• Without a birth time, the chart is drawn for noon and the rising sign and houses are left out rather than guessed.

The calculators on the guide pages (sign lookups, Saturn returns, retrogrades, moon phases) use tables generated from the same engine and checked against it.

How the pages are written and checked

Every placement, degree and date on a page comes from the chart engine, not from memory or other sites, and our tests fail if a page names a Sun, Moon or rising sign the chart doesn’t have. Interpretations are written to be plain and to lead with strengths.

Celebrity birth charts only use a birth time the person gave themselves: a post, an interview, a live stream, a tattoo or their own birth certificate. Each page links its source. When a time is rounded or estimated, or when a different time is on record elsewhere, the page says so and explains what would change. People who have never shared a time get a page that says exactly that, with the chart for the day and no rising sign.

Famous moments (launches, landings, the Bitcoin genesis block) use a logged time from a primary source, linked on each page.

Personal readings are written by an AI model from your computed chart, and Pluto, the chat on your chart page, is an AI as well. Neither one changes the chart itself. What’s sent to the model is set out in the privacy policy.

Corrections

If a birth time, source or date on a page is wrong, or a newer first-hand source exists, write to mail@pluto.garden with a link. We check it against the source and update the page and its date.

Contact

Anything else: mail@pluto.garden. Privacy questions go to the address in the privacy policy. Pluto Garden also works inside AI assistants: see the connector for Claude and ChatGPT.