See it
Start with a view you can explore, not a diagram you have to take on trust.
Open eclipse maps · local predictions · reusable code
See the shadow. Then look behind the prediction.
Shadowline turns the predicted motion of the Sun and Moon into an explorable model of a solar eclipse. Follow the shadow across Earth, check what happens at a place, and see what the calculation can—and cannot—tell us. Then use the open code behind the view to make an eclipse visualisation of your own.
- Calculated in your browser
- Projection-neutral WGS 84 geometry
- Open-source packages and GIS exports
From model to visualisation
One open model. Many ways to make it meaningful.
These are two examples, not two limits. The explorer compares eclipses across dates, places and projections. The 2026 tracker reshapes the same underlying geometry around one event, one observer and one day.
General-purpose explorer
Browse solar eclipses
Find eclipses by year or place, compare a flat map, a physical Earth–Moon view, the whole Earth and local terrain, then download the complete geometry as GeoJSON or KML.
- Any year or selected location
- Four coordinated views
- Portable planning data
Focused field application · 12 August 2026
Take the tracker with you
Use your location to see local eclipse times, preview the Sun, and follow the moving shadow. Load it before you set out and it can keep calculating if your signal drops.
- Location-aware contact times
- Live and manual time preview
- Designed for a poor connection
How Shadowline works
Build the model once. Ask many questions of it.
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01
Start with a celestial model
Astronomy Engine supplies predicted Sun and Moon positions. Shadowline transforms them into a rotating, Earth-fixed frame.
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02
Calculate the physical geometry
The shadow cone is intersected with the WGS 84 shape of Earth. The complete path stays independent of any particular map projection.
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03
Shape a view around a real question
The explorer, ground view and 2026 tracker each select and present the shared geometry differently. A new application can ask something else without having to rebuild the eclipse science.
Part of Found in Space
See it. Question it. Build with it.
Found in Space turns open scientific measurements and models into interactive experiences, while keeping the sources, assumptions and limitations in view. A compelling picture should invite the next question: what is this made from, what does it leave out, and what can I make with the material behind it?
Shadowline is not only something to use. It is a public, package-first codebase: renderer-independent geometry, an astronomy adapter, GIS exporters and working example applications. Use one piece, replace a renderer, make a classroom activity, or take the model somewhere the current site does not go.
Start building
Use the eclipse engine, not just the website.
Install the geometry package and its Astronomy Engine provider, then calculate a path, local circumstances or GIS export inside your own JavaScript or TypeScript project.
npm install @found-in-space/shadowline @found-in-space/shadowline-astronomy-engine
Question it
Keep evidence, transformations, assumptions and uncertainty close to the result.
Build with it
Install the packages, fork a working example, or contribute the next useful way to see the model.
Ready to take it further?
