Inspector
--:--:--
Loading…
Location
Detecting…
—
--:--:--
Loading…
Location
Detecting…
—
A live data explorer for the astronomy engine shared by Chronometer and Observatory — rise/set times, planetary positions, and calendar and clock values, at any time and location.
View the project on GitHub · Credits · Privacy · Support · Disclaimer
Your settings are saved in this browser's local storage on this device. Use the Share button to copy a link to a view. See Privacy for more information.
A web port of Emerald Chronometer (GitHub), an astronomical watch-face app originally built for iPhone and iPad.
A web port of Emerald Observatory (GitHub), an astronomical clock app originally built for iPad.
A live data explorer for the astronomy engine shared by Chronometer and Observatory — rise/set times, planetary positions, and calendar and clock values, at any time and location.
Thirty years of solar and lunar eclipses, each with links that open the moment and place of maximum eclipse in Observatory and Chronometer.
Emerald Inspector for the Web
Emerald Inspector for the Web is a fully client-side application. It runs entirely in your browser and does not communicate with any application server for its core functionality.
The app itself does not collect, store, or transmit any personal data to any application server. There are no app-level analytics, tracking pixels, cookies, or telemetry of any kind.
When the app is served over HTTP or HTTPS, the hosting provider (SiteGround) records standard web server access logs for each page and resource request. These logs include:
These logs are retained by SiteGround for up to 30 days and are used solely for security monitoring and troubleshooting. They are not analyzed for user tracking purposes.
When running from file:// URLs (a local copy of the app), no
server is involved and no logs are generated.
When you use the location dialog (on pages served via http:// or
https://), the app fetches map tile images from
OpenStreetMap
to display a preview of the selected location.
These requests are standard image fetches and do not include any metadata identifying the tile coordinates as your location — OpenStreetMap sees only which map tile was requested, the same as any map browsing.
If you tap "Use device location via browser", the app uses the browser's Geolocation API to obtain your coordinates. This data is processed entirely within the browser — the app never sends it to any application server.
The resolved coordinates are matched against a bundled database of approximately 47,000 cities to display a human-readable location name. This reverse-geolocation lookup happens entirely in the browser — no external geocoding service is contacted.
The app saves your settings (location, time, and per-app configuration) in your browser's local storage — on your device only. This data is never sent to any application server, and it persists across visits without any cookies.
You can clear local storage at any time through your browser's settings (typically alongside your browsing history).
When you use the Share button, the app builds a URL that encodes the current view so you can send it to someone else or open it on another device. Opening such a link lets you either use those settings just for that visit or save them as your defaults.
Note: Because shared links carry settings as URL query
parameters, those parameters are visible in your browser history and, when
served over HTTP or HTTPS, in the hosting provider's access logs — but only for
links you deliberately create or open. On file:// pages where
local storage is unavailable, the app falls back to keeping settings in the
URL.
For questions about this privacy policy, please visit the project on GitHub.
Last updated: May 2026
Emerald Inspector for the Web
Found a bug? Please report it on the GitHub issues page. Describe what you saw and what you expected, and mention which app and which browser and device you were using, along with the app’s version number (shown at the bottom of the help popup opened by the ℹ︎ button, e.g. “v2.1.8”).
This free web app is maintained by volunteers, so no support or response time is promised — but the developers do read the reports and fix most bugs.
The website itself only serves, as a convenience, files available from the GitHub releases page (see instructions for running the app here).
Emerald Inspector for the Web
THIS FREE WEB APP IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
The pages served to your browser are available at the GitHub releases page (see instructions for running the app here).
Values are grouped Time → Sun → Moon → Eclipse → Mercury … Neptune. Angles are in degrees; rise, set, and transit are local times at the configured location (shown as "—" when the event does not occur, for example during polar day or night); distances are given in both astronomical units and kilometers. Each planet shows two distances: geo (from Earth) and helio (from the Sun), qualified the same way as its ecliptic coordinates. Each value is fully re-evaluated on its own schedule (fractional seconds many times per second, coordinates every second, rise/set times once a minute) and animated smoothly in between.
An eclipse needs two things at once: a new or full moon, and the Moon near the plane of Earth's orbit. The Eclipse group shows both conditions and the verdict. Separation is how close the Moon is to new or full — the Moon−Sun difference in ecliptic longitude (0° at new moon, 180° at full) and the true angular elongation. Moon ecl. lat is the Moon's distance from the ecliptic plane; an eclipse requires it to be near zero, which happens when the Moon is near one of its orbit's nodes. Nearest node is the node the Moon is currently closest to — ascending or descending, the crossing the Moon just made or is about to make — with its ecliptic longitude and how far it sits from the point where new or full moons occur. When that gap is small, the Moon reaches new or full just as it crosses the ecliptic there, and an eclipse follows. Level is the eclipse indicator shown on the Basel watch face: the needle value runs from 0 to 3 (below 1 a total eclipse is in progress, 1–2 partial, above 2 none), and the kind text matches Basel's wheel — None, Sun/Moon not up, Partial/Annular/Total Solar, or Partial/Total Lunar.
Chronometer and Observatory never display a value more precisely than the underlying astronomical algorithms can support. The Inspector deliberately breaks that rule: its readouts show more digits than the engine's accuracy warrants. The extra digits are there so you can watch a value move — how fast it is changing, in which direction, and when it reverses — which a data explorer can only show by running past the point where the digits stop being meaningful. Treat the trailing digits as rate information, not as measurement; the engine's real accuracy is described in "Accuracy of the Astronomical Algorithms" under General Help Topics, above.
The time controller (under the clock) and the location card work exactly as in Chronometer and Observatory, and all three apps share their settings — set a time or place here and the other apps follow. The Browser time row at the bottom of the Time group shows your device's raw clock for comparison with the Inspector's display time; it is dimmed while the clock is stopped.