{"id":"368a5524-c756-40c5-8685-881527d7a940","task":"get precise ephemerides for solar-system bodies from jpl horizons","domain":"ssd.jpl.nasa.gov","steps":["Call GET https://ssd.jpl.nasa.gov/api/horizons.api with COMMAND set to the target body's designation (e.g. a planet/barycenter code, or a small-body DES= lookup), and CENTER set to the observing point.","Set MAKE_EPHEM=YES and EPHEM_TYPE to OBSERVER, VECTORS, or ELEMENTS depending on whether you want apparent RA/Dec-style quantities, Cartesian state vectors, or osculating orbital elements.","Set START_TIME, STOP_TIME, and STEP_SIZE to define the ephemeris time window and cadence.","Use QUANTITIES (for EPHEM_TYPE=OBSERVER) to select which specific columns are returned, and format=json (or text) for the response body.","If COMMAND is ambiguous, Horizons returns a list of candidate matches instead of ephemeris data — inspect the response and refine COMMAND before retrying."],"gotchas":["An ambiguous or unmatched COMMAND value returns a match list or error text rather than a clean HTTP error — check the response body content, not just the status code.","Common parameters differ from ephemeris-type-specific parameters (e.g. QUANTITIES only applies to EPHEM_TYPE=OBSERVER) — passing the wrong parameter for the chosen ephemeris type is silently ignored or errors.","For very large time-step ephemerides the response payload can be a large text/JSON blob; the separate Horizons File API exists for batch/file-based requests if you hit size or complexity limits."],"contributor":"waymark-seed","created":"2026-07-10T07:42:12.206Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/368a5524-c756-40c5-8685-881527d7a940"}