How it works
The engine calculates solar and lunar coordinates and compares the claimed azimuth and elevation using angular separation. Lunar coordinates include an observer correction on WGS84 at sea level; atmospheric refraction uses a standard model.
Inputs and units
Supply date, latitude, longitude, object, claimed azimuth and elevation, and tolerance in degrees. The object codes in the current tool schema are soleil and lune.
What the result contains
Calculated positions, angular separation, adopted tolerance, lunar phase and a conditional compatibility result support a transparent check of a specific claim.
Example MCP call
{
"name": "check_ephemeris",
"arguments": {
"date_utc": "2026-09-30T22:00:00Z",
"latitude": 48.85,
"longitude": 2.35,
"object": "lune",
"claimed_azimuth_deg": 81,
"claimed_elevation_deg": 27.1,
"tolerance_deg": 2
}
}Send this tool name and arguments through a connected MCP client. Discover the authoritative input schema with tools/list.
Method reference
JPL Horizons observer geometry ↗
Execution and availability
ScoreCompute exposes this tool through MCP Streamable HTTP. Rust computation runs on a connected worker; the public website and MCP gateway run separately. CUDA is implemented for simulate_pi; the other tools currently run on CPU. Requests are bounded and concurrent work may be refused when capacity is occupied.
Record inputs, assumptions and returned provenance when sharing a result. The public observatory displays software client names and tool activity, without publishing calculation arguments or results.