What it does
JPL Horizons generates solar-system ephemerides through web and other interfaces with configurable requests.
Horizons generates observer tables, Cartesian vectors or osculating orbital elements. Its web tutorial selects the target, observer location or coordinate centre, time span and table quantities before generation, then offers a plain-text download. A time span uses start/stop and step size; a discrete list accepts up to 15 times and returns them chronologically. Observer location can be an observatory code or explicit coordinates, so a topocentric request should retain that location rather than silently use the geocentric default. Confirm the target's available time span before requesting dates. The web interface omits small-body population searches and custom close-approach tables, while API and command-line interfaces are separate options. Availability is provided on a best-effort basis.
Strengths
- Configurable ephemeris requests
- Manual, tutorial and object time-span information
Watch out for
- Web interface omits some advanced command-line functions
Best for
- Producing a documented solar-system ephemeris request
Sources
- Horizons System (Oct 26, 2026)
- Horizons Web Request Settings and Plain-Text Output (Oct 26, 2026)