# Sun, Moon and Planets

Sun and Moon position, rise and set, twilight, planets, equation of time and eclipse checks.

## How to pay

Machine-payable over x402. USDC on: Base (eip155:8453), Solana (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp), Polygon (eip155:137), Arbitrum One (eip155:42161).
No accounts. No API keys. No signup. The paying wallet is the account.

## Machine-readable

- OpenAPI: https://sky-calc.x402tookit.com/openapi.json
- x402 manifest: https://sky-calc.x402tookit.com/.well-known/x402
- Catalog (free): https://sky-calc.x402tookit.com/catalog
- Health (free): https://sky-calc.x402tookit.com/health
- Uptime (free): https://sky-calc.x402tookit.com/uptime

## Endpoints (8)

### GET /eclipse-check — $0.02
Can a solar or lunar eclipse happen at the new and full moon nearest a date? Type, ecliptic-latitude margin and syzygy times.
Params: date: string
Example: https://sky-calc.x402tookit.com/eclipse-check?date=2024-04-08

### GET /equation-of-time — $0.02
Equation of time in minutes for a date (sundial minus clock), and the clock time of solar noon at a longitude.
Params: date: string, time?: string, lon?: number
Example: https://sky-calc.x402tookit.com/equation-of-time?date=2026-11-03&lon=-74.006

### GET /moon-position — $0.02
Moon azimuth and altitude for a lat/lon and UTC moment, plus distance in km, illuminated fraction, phase and parallax.
Params: lat: number, lon: number, datetime?: string, date?: string, time?: string
Example: https://sky-calc.x402tookit.com/moon-position?lat=51.5074&lon=-0.1278&datetime=2026-10-20T20%3A00%3A00Z

### GET /planet-positions — $0.02
Geocentric ecliptic longitude/latitude, RA/Dec, distance and Sun elongation for Mercury to Neptune; arcminute accuracy.
Params: datetime?: string, date?: string, time?: string, planets?: string
Example: https://sky-calc.x402tookit.com/planet-positions?datetime=2026-10-20T00%3A00%3A00Z&planets=venus%2Cmars%2Cjupiter%2Csaturn

### GET /planet-visibility — $0.03
Which planets are above the horizon an hour after sunset for a lat/lon and date: altitude, azimuth, elongation, set time.
Params: lat: number, lon: number, date: string, utc_offset_hours?: number
Example: https://sky-calc.x402tookit.com/planet-visibility?lat=40.7128&lon=-74.006&date=2026-10-20&utc_offset_hours=-4

### GET /rise-set-moon — $0.02
Moonrise, moonset and transit for a lat/lon and local date, with azimuths and illumination; handles days with no rise or set.
Params: lat: number, lon: number, date: string, utc_offset_hours?: number
Example: https://sky-calc.x402tookit.com/rise-set-moon?lat=51.5074&lon=-0.1278&date=2026-10-20&utc_offset_hours=1

### GET /rise-set-sun — $0.02
Sunrise, sunset, solar noon, three twilights, golden and blue hour for a lat/lon and date; handles polar day and night.
Params: lat: number, lon: number, date: string, utc_offset_hours?: number
Example: https://sky-calc.x402tookit.com/rise-set-sun?lat=40.7128&lon=-74.006&date=2026-06-21&utc_offset_hours=-4

### GET /sun-position — $0.02
Sun azimuth and altitude for a lat/lon and UTC moment, with refraction-corrected altitude, RA/Dec, distance and twilight phase.
Params: lat: number, lon: number, datetime?: string, date?: string, time?: string
Example: https://sky-calc.x402tookit.com/sun-position?lat=40.7128&lon=-74.006&datetime=2026-06-21T16%3A00%3A00Z

## Terms

Computed locally from published low-precision algorithms (Meeus, Schlyter). Accuracy is stated per endpoint; not for navigation, surveying or safety-critical use. Never look at the Sun without proper eye protection.