retrograde

No-BS astrological calculations validated against NASA, JPL Horizons & Swiss Ephemeris. Birth charts, transits, progressions that actually work.

Is Mercury retrograde today? The answer for any date, the next retrograde and its shadow periods, the loop Mercury draws in the sky, and the year's retrogrades for every planet.

the period that the planet retrograde ocurring

Data, code, images, and text to enlarge one's world

A quick way to set up Retrograde Engine projects

Reproducible astrology studies with scripts (MIT) and CSV (CC BY 4.0): the rarest zodiac sign in 710 million births, rising signs by latitude, MC in the whole-sign 10th house, planetary retrogrades 1900–2100, and chart features in 95.7 million real births.

A live orrery and Earth's-eye sky, in one dependency-free HTML file. Real planetary positions from JPL elements; watch Mars draw its retrograde loop against real stars.

Transit forecast API. Astrology transits to natal aspects, sign ingresses, retrograde stations, eclipses, new and full moons. Exact instants.