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Astronomy MCP Server

Offline observational astronomy: positions, rise/set, moon phases, eclipses, and seasons.

Connector by cyanheads · GitHub account verified by the MCP Registry

IndexedApache-2.0Local (stdio)Remote (HTTP)★ 3
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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/mcp Remote (HTTP)

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About

Offline observational astronomy: positions, rise/set, moon phases, eclipses, and seasons.

No 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_events
  • astronomy_get_ephemeris
  • astronomy_get_moon_phase
  • astronomy_get_rise_set
  • astronomy_get_satellite_passes
  • astronomy_get_sky_position
  • astronomy_list_visible

Secrets and settings it asks for

Other settings (environment variables or headers).

  • ASTRONOMY_DEFAULT_TIMEZONE
  • ASTRONOMY_ENABLE_HORIZONS
  • ASTRONOMY_ENABLE_SATELLITES
  • MCP_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-only

    Search 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-only

    Fetch 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-only

    Report 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-only

    Compute 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-only

    Predict 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-only

    Compute 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-only

    The 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
License
Apache-2.0
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

More from cyanheads

Cite this page

Astronomy MCP Server. Agent Mart. https://agentmart.dev/connectors/cyanheads-astronomy-mcp-server (last updated 2026-10-24)