How We Calculate Your Chart

Where the Data Comes From

The planetary positions you see on your chart don't come from simplified tables or rough estimates. We use Skyfield, a real astronomy library built on JPL ephemeris data (NASA's Jet Propulsion Laboratory) — the same astronomical data used to calculate orbits and planetary positions with scientific precision. That means when your chart says Venus was in a particular sign and degree on the day you were born, that's a real astronomical calculation, not a rounded estimate based on a date range.

How the Chart Is Built

Using your exact birth date, time, and place, we calculate the position of every planet and the twelve astrological houses using the Placidus system, one of the most widely used in Western astrology. If you don't know your exact birth time, we show you a sun chart instead — calculated for local noon — which gives reliable planetary positions but no accurate ascendant or houses, since both depend directly on the exact time. All of the calculation happens right in your own browser: your birth data is never sent to any server of ours. No one on our team sees or stores that information — it's calculated on your device, and that's it.

How the Texts Are Written

The interpretations you read next to each planetary position are drafted with the help of AI, based on the already-calculated astronomical positions, and then go through human editorial review before publishing. We don't invent a flesh-and-blood astrologer behind each text, and we don't hide that AI is part of the process — we're saying it here, as plainly as we explain where the data comes from.

Who We Are

Astro Mapa is built by a small, independent team, not a media company or a large horoscope publisher. We built this because we're genuinely interested in astrology as a tool for self-understanding, and we wanted an honest version of how it actually works under the hood — no invented credentials, no dressing up the process.

What We Do (and Don't) Believe

We treat astrology as a symbolic language for thinking about yourself, your patterns, and your cycles — not as a system that predicts specific events in your future. We won't tell you when you'll land a job, when you'll meet someone, or whether a deal will work out. What we do offer is a detailed chart, calculated with real astronomical precision, so you can draw your own conclusions about who you are and how you move through the world.