EARTH ORBIT · DATA & VALIDATION
Research
Choose a time. Compare models. Take the data with you.
2026–2027 reference data · with reference checksFor 2027 we assume TT−UTC = 69.184 s. Future leap seconds are not predicted; this time conversion is provisional.
Earth–Moon barycenter relative to the center of the Sun. Geometric, J2000 ecliptic; not an apparent sky position.
Take the data with you
Exports include UTC, TDB, position and velocity vectors, distance, speed, longitude and model version. JSON also includes source, validation and limitations. Daily export: 00:00 UTC.
How accurate is the calculation?
Daily NASA/JPL Horizons DE441 positions and velocities provide the source. Cubic Hermite interpolation fills the intervals. Validation uses separate reference samples between the source nodes.
| Quantity | Research module | Home-page model |
|---|---|---|
| Distance | ||
| Speed | ||
| Ecliptic longitude |
These are observed residuals against the same JPL source, not guaranteed error bounds. DE441 uncertainty, time conversion and device clock errors are not included. This is not independent scientific certification.
Method and limitations
The home page uses approximate Keplerian elements; this research module uses stored Horizons vectors. The motion of Earth’s center around the Earth–Moon barycenter is not included. These are not exact Earth-center positions.
Input is UTC. For 2026–2027 we use TT−UTC = 69.184 s (provisional for 2027) and an approximate periodic TDB−TT correction. Interpolation validation uses TDB epochs and does not test this conversion. No extrapolation is performed outside the reference period.
The clock follows your device. Live means calculating the current state from stored ephemeris data, not live satellite measurements. Clouds and backgrounds do not provide research data.
Source & reproducibility
Target: Horizons 3 · center: 500@10 · ECLIPTIC / ICRF · KM-S · TDB · VEC_CORR=NONE.
Source files have a SHA-256 checksum in their metadata. Query settings make the comparison reproducible. This module does not request your location.