Open Ephemeris gives ChatGPT real astronomy to work from. Every position comes from the NASA JPL DE440 ephemeris covering 1550-2650 CE at sub-arcsecond precision, the same kernel used for spacecraft navigation, so positions are computed rather than estimated. Ask for a natal chart and an interactive wheel opens in the conversation. Click a planet, a house, or an aspect line and the interpretation loads in place. Switch house systems without asking again. The same applies to Human Design bodygraphs, synastry bi-wheels, transit timelines, Vedic Rashi grids and BaZi Four Pillars charts. Beyond charts: transits and progressions, solar and lunar returns, eclipse timing and local visibility, astrocartography, electional search for timing windows, and fixed-star positions. Free to start, no card required.

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Open Ephemeris