Solar Eclipse

Why we love it

The Solar Eclipse Finder map underscores why people are enthralled by these rare, fleeting celestial events. This map is your guide to one of nature’s most spectacular shows, detailing eclipse duration and the path of the moon's shadow. A quick demo shows how to use the map. A binary color scheme (green for past and orange for future) simplifies the experience and makes a legend unnecessary. We love how you can click a location to reveal any of the 905 solar eclipses between the years 1601 to 2200.

Why it works

Here is a great example of the notion that sometimes “the map is the interface.” Within the Solar Eclipse Finder map, details emerge as you explore each location and each solar eclipse path. Rather than plot the paths as solid blocks, the map author uses gradient effects and line tapering. The map works because it gives an accurate portrayal of events and provides an evocative experience. Going beyond standard techniques, the map’s gradient effects capture the graceful and sweeping nature of an eclipse.

Important steps

Choose an app template

Choose the appropriate app template to showcase your work, or quickly create a custom one using AppStudio for ArcGIS. Embedding the map inside an app provides added control and polish to the user experience.
Download popover tool and modal dialog

This application uses Bootstrap’s popover tooltips in the fly-out attribute window and its modal dialog during start up.

Bring Bootstrap's components to life
Get tapered symbol with a linear gradient fill

The tapered symbol used by eclipse shadow paths is achieved with a linear gradient fill, supported by SVG—the underlying technology used for rendering vectors in Esri’s ArcGIS Maps SDK for JavaScript.
Use a muted basemap

To give emphasis to the eclipse paths, use a muted basemap, or style your own using vector tiles in ArcGIS Pro.

Author a map for vector tile creation

Data and software

The eclipse paths were prepared by Michael Zeiler from data courtesy of Xavier Jubier. The basemap is Esri's Light Gray Canvas. Software used: ArcGIS Online, ArcGIS Maps SDK for JavaScript, ArcGIS Pro, and AppStudio for ArcGIS.

Eclipse maps and more by Michael Zeiler

Solar eclipse data
Analysis

With the analysis of the 905 paths pre-calculated for the years 1601 to 2200, the map plotted the source data as an ArcGIS Online hosted service. No additional analysis was needed.
Time

Development time was minimal, about two days, since the data was ready to plot. Most of this time was spent pushing the capabilities of HTML5/JavaScript to support advanced styling.

Use photos explaining annular/total solar eclipses

This app shows both annular and total solar eclipses. While the concepts are simple, the terminology might not be familiar. Visuals help to explain.
Go easy with the UI

This map needs almost no UI since you can just click to see the information you want, and hover over the UI elements to go deeper.
Keep explanations brief

Showing concise explanations via tooltips helps readers learn and explore at their own pace.