# Cyclecalcs Astronomy MCP server

Source: https://glimind.com/server/mcp-registry%2Fcom.cyclecalcs%2Fastronomy
Registry id: `mcp-registry/com.cyclecalcs/astronomy`
Status: live (checked 2026-10-27T03:23:57.190Z)

## Verdict

Cyclecalcs Astronomy MCP server answered 99.97% of Glimind's liveness checks over 30 days, better than 42% of MCP servers, with 2363 ms median handshake and 5 outages in 90 days. Its agent-readiness grade is A (92/100) across 11 tools, costing an agent about 9,481 tokens to load. Checked every few minutes; no tool is ever called.

## Measurements (30 days)

| Metric | Value | Better than |
|---|---|---|
| Uptime, 30 days | 99.97% | 42% of MCP servers |
| Median handshake latency | 2363 ms | 3% of MCP servers |
| p95 handshake latency | 4954 ms | — |
| Checks in 30 days | 4,976 | — |
| Outages, 90 days | 5 | — |
| Median recovery | 19 min | — |
| Agent-readiness score | 92/100 (A) | 73% of MCP servers |
| Tools | 11 | — |
| Tool-list size for an agent | ~9,481 tokens | 31% of MCP servers |
| Days observed | 29 | — |

## Install

```json
{
  "mcpServers": {
    "cyclecalcs-astronomy-mcp-server": {
      "type": "http",
      "url": "https://www.cyclecalcs.com/mcp"
    }
  }
}
```

Claude Code:

```sh
claude mcp add --transport http cyclecalcs-astronomy-mcp-server https://www.cyclecalcs.com/mcp
```

## Tools (11)

- `astro_dark_window`: The genuinely dark, moonless observing window for a night: astronomical night intersected with the Moon being down, ranked across up to 62 nights with a trend. 
- `astro_eclipses`: Solar and lunar eclipses: the next or previous from a date, or all in a range, with type, magnitude, obscuration, Saros series and global geometry. A solar ecli
- `astro_find_place`: Resolve a place name to coordinates, region, country, IANA timezone and a stable place_id, or reverse-look-up the nearest places to a lat/lon. Results are GeoNa
- `astro_moon`: The Moon at an instant or as a daily series: phase name and angle, illuminated fraction, distance, apparent size, libration, bright limb, and the next quarter p
- `astro_moon_phases`: Every new moon, quarter and full moon in a window (or the next few from a date): each with its exact instant, distance, apparent size, supermoon classification 
- `astro_planet_board`: All eight planets in one call for a date and optional location: constellation, magnitude, apparent size, elongation from the Sun, morning or evening sky, retrog
- `astro_planet_events`: Dated planet events. For Mercury and Venus, the apparition cycle: inferior and superior conjunctions, greatest eastern and western elongations, peak brightness 
- `astro_positions`: Exact positions for up to 20 bodies at an instant or over a time grid: right ascension and declination in both J2000 and of-date frames, ecliptic longitude and 
- `astro_rise_set`: Rise, upper transit, set and lower transit for one body at one location, with an explicit status at extreme latitudes (circumpolar, never rises) instead of miss
- `astro_sky_today`: One-call snapshot of the whole sky for a place and moment: moon phase and illumination, which planets are up and worth looking at, the next eclipse, and (with a
- `astro_sun`: The complete solar day for one location: sunrise, sunset, solar noon, day length, civil, nautical and astronomical twilight boundaries, and explicit polar day/n

Measured by Glimind (https://glimind.com): MCP handshake + tool list only, no tool is ever called. CC BY 4.0.