Exploring Solar Eclipses with GIS
There are very few topics to which GIS cannot add understanding. One fun and engaging example is the examination of solar eclipses, illustrated in this short lesson with a data set that you can dig into with your students, to foster spatial thinking, critical thinking, content knowledge about Earth-Sun relationships, and engagement with mapping tools.
Solar eclipses represent an excellent theme for study for three key reasons. One, it is anchored in key concepts of Earth science, geography, mathematics, and astronomy and thus teaching the topic bridges these disciplines. Two, they exhibit spatial patterns that can be effectively analyzed using GIS. Three, they afford the opportunity, particularly for those in the path of one, to get out into the field to observe. Careful, though! -- use eye protection and get to a place you can safely observe without having to worry about vehicles or other potential hazards.
Once again, ArcGIS Online comes through as an amazing content library: An investigation of possible content in ArcGIS Online resulted in a feature service containing 905 solar eclipses from 1601 to 2200! That means that it includes future projections as well. Impressive and definitely will meet my needs!
https://services.arcgis.com/6DIQcwlPy8knb6sg/arcgis/rest/services/SolarEclipsePath/FeatureServer
After adding this data to the ArcGIS Online Map Viewer, I filtered on date and got these results shown below for the next two that I and those near me in North America might experience – Oct 2023 and Apr 2024.
My resulting map is here for you to use in your own investigation (or of course you could create your own!):
https://www.arcgis.com/apps/mapviewer/index.html?webmap=7cb5db9c130a46709bcc7abe7060fa4e
Questions to pose to students include the following:
- Describe the shape of the eclipse paths. Use some directional components in your description.
- Why do the eclipse paths have the shape they do?
- How are the eclipse paths predicted into the future in this data set?
- Which cities and regions will be able to see these selected eclipses?
- Will you be able to view these eclipses where you live?
- If not, how far away (use the measure tool) will you need to travel to see the eclipse?
- Will the eclipse be total during the entire width of each path, or only in the center of each?
- Will the eclipse be total during the entire length of each path, or only for a portion of each path?
A 3D scene may enhance the learning experience. Before creating one, so that all eclipses are not rendered atop the 3D scene (it works, but it looks rather like spaghetti on a beach ball), I first saved my filtered data set, added it to a 3D scene, saved, and shared it with you, here:
https://www.arcgis.com/home/webscene/viewer.html?webscene=463f080222cf4928919a3c51b6384672
Since the content and tools in the modern GIS cloud-based environment are so rich, additional topics can also be examined using GIS. For example, use the data and time slider in the 3D scene viewer to determine what the sun angle at the time of the solar eclipse will be where you are, as shown here:
As the time draws closer for a particular eclipse, use the real-time weather feeds and forecasts in ArcGIS Online to determine what the cloud cover might be during the scheduled eclipse time. Consider landforms in your area--will any mountains or canyon walls obscure your view during certain times of the day?
Angles, sun, Earth, measurement, scale, and more---all of these are rich opportunities to foster spatial thinking.
- What additional questions could you pose with this data set and these tools?
- Lunar eclipses, analyzing sunrise and sunset times, analyzing proposed building construction and areas of a community that would potentially be in shadow, time zones, and locations of meteorite impacts are just a few of the topics that can be studied with GIS. What additional Earth-Sun-Moon relationships could you model and foster understanding using GIS?
I look forward to your comments.
--Joseph Kerski