Astronomy MCP Server
Offline observational astronomy: positions, rise/set, moon phases, eclipses, and seasons.
Connector by cyanheads · GitHub account verified by the MCP Registry
Install
Works with Claude Code, VS Code, Codex, Cursor, Windsurf, Claude Desktop. Read the repository before you give any tool access to your data.
npx agentmarket install connector/cyanheads-astronomy-mcp-server
Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.
Remote endpoint
https://astronomy.caseyjhand.com/mcpRemote (HTTP)
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About
Reviews
Write a reviewNo reviews yet. Installed it? Reviews come from verified installers only. How reviews work
Permissions
What this server can do and what it asks for, from its tool list and install config. Checked Oct 25, 2026.
- Tools
- 7 read · 0 write · 0 deleteRead-only
- Secrets
- None asked for
- Install scripts
- Not scanned yet
- Runs as
- Node.js package
Tools by what they do 7
From the running server's own tool list (tools/list) on Oct 25, 2026.
Read 7 · Look things up without changing anything.
astronomy_find_eventsastronomy_get_ephemerisastronomy_get_moon_phaseastronomy_get_rise_setastronomy_get_satellite_passesastronomy_get_sky_positionastronomy_list_visible
Secrets and settings it asks for
Other settings (environment variables or headers).
ASTRONOMY_DEFAULT_TIMEZONEASTRONOMY_ENABLE_HORIZONSASTRONOMY_ENABLE_SATELLITESMCP_LOG_LEVEL
Network hosts it talks to 1
astronomy.caseyjhand.com· found in remote endpoint, install command
Tools (7)
As the server listed them on Oct 25, 2026. Descriptions are the server’s own words; hidden characters are shown as [U+…].
astronomy_find_eventsastronomy-mcp-server: find sky eventsread-onlySearch forward from a start time for the next occurrences of one sky-event class, selected by the `event` enum: solar_eclipse, lunar_eclipse, equinox, solstice, moon_quarter, opposition, conjunction, max_elongation, or perigee_apogee. Both eclipse classes take an optional observer (latitude and longitude together). solar_eclipse without one returns global eclipses — kind, peak time, obscuration, and for a total or annular eclipse the latitude/longitude where it is greatest; with one it returns only eclipses visible from that point, with local contact times, `local_visible`, and the Sun's altit…
astronomy_get_ephemerisastronomy-mcp-server: get small-body ephemerisread-onlyFetch a time-series ephemeris for a small body (asteroid or comet) or spacecraft from JPL Horizons — RA/Dec, distance, and apparent magnitude over a span, optionally with observer-relative altitude/azimuth. This covers objects the in-process major-body set cannot. The designation is passed to Horizons verbatim, so it must be in a form Horizons resolves to a single record: a numbered asteroid takes a trailing-semicolon record lookup (e.g. "433;" for Eros, "1;" for Ceres), and a periodic comet takes the DES + closest-apparition form (e.g. "DES=1P;CAP" for Halley). Spacecraft take their negative …
astronomy_get_moon_phaseastronomy-mcp-server: get moon phaseread-onlyReport the Moon phase for an instant: illuminated fraction, phase name, synodic age in days since the new moon, phase longitude (the Moon–Sun ecliptic-longitude difference, 180° at full), and the next four quarter phases (new, first quarter, full, last quarter) with timestamps. Answers "what is the moon phase tonight" and "when is the next full moon" in one call without iteration. The time defaults to now; pass an IANA `timezone` to also receive observer-local timestamps. The phase is geocentric — no observer location is needed.
astronomy_get_rise_setastronomy-mcp-server: get rise/set timesread-onlyCompute rise, set, and culmination (transit) times and maximum transit altitude for a body at an observer location. Searches forward from `start` (default now) for `count` daily cycles (default 1), including days without crossings. For the Sun, each cycle carries civil −6°, nautical −12°, and astronomical −18° twilight: dusk after its set or culmination, then dawn before the next day begins. A crossing absent from that night is null. When the Sun is down and the first cycle's day begins after `start`, `night_in_progress` carries the preceding night, including polar nights without a sunset and …
astronomy_get_satellite_passesastronomy-mcp-server: get satellite passesread-onlyPredict visible passes of a satellite (e.g. the ISS, NORAD 25544) over an observer in the next `days`. Identify the satellite by exactly one of `norad_id` or `name` — supplying both, or neither, is rejected. A few well-known common names resolve directly to their catalog numbers, ignoring case: ISS or International Space Station (25544), Hubble, Hubble Space Telescope, or HST (20580), and Tiangong, CSS, or Chinese Space Station (48274). Any other `name` is matched as a case-insensitive substring of CelesTrak's catalog names, so it resolves only when it picks out a single object: a broader quer…
astronomy_get_sky_positionastronomy-mcp-server: get sky positionread-onlyCompute the apparent topocentric position of one solar-system body (sun, moon, mercury through neptune, pluto) or a named bright star for an observer location and instant. Returns equatorial (RA/Dec), refraction-corrected horizontal (altitude/azimuth), and ecliptic coordinates, plus distance, apparent magnitude, angular diameter, phase angle, illuminated fraction, angular distance from the Sun, and the constellation it falls in. For a solar-system body it also returns that body card — classification, mean radius, naked-eye visibility — the same values served at astronomy://body/{body}, so a cl…
astronomy_list_visibleastronomy-mcp-server: list visible bodiesread-onlyThe one-call "what is up right now" answer. For an observer location and instant, iterate every naked-eye solar-system body (and, with include_stars, the bundled bright stars), compute altitude and azimuth, keep those above the horizon, rank them brightest-and-highest first, and attach a plain-language visibility note to each, along with its angular distance from the Sun. The whole sky is gated by the Sun's altitude into daylight / civil / nautical / astronomical twilight / dark, returned alongside the list, and each note says when daylight, civil twilight, or the Sun's glare hides or dims tha…
Signals
- Stars
- 3
- Forks
- 1
- Open issues
- 3
- Weekly downloads
- 185
- Last commit
- Oct 17, 2026 (11 days ago)
- Last release
- Oct 15, 2026 (13 days ago)
- Last package publish
- Oct 15, 2026 (13 days ago)
From GitHub (fetched Oct 24, 2026) and the package registry.
Details
- Registry name
io.github.cyanheads/astronomy-mcp-server- Version
- 0.4.2
- Auth
- Auth not stated
- Packages
- npm @cyanheads/astronomy-mcp-servernpm @cyanheads/astronomy-mcp-server
- License
- Apache-2.0
- First seen
- Oct 24, 2026
- Last checked
- Oct 24, 2026
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Cite this page
Astronomy MCP Server. Agent Mart. https://agentmart.dev/connectors/cyanheads-astronomy-mcp-server (last updated 2026-10-24)