Abstract

We describe the features of the Annular Eclipse Cosmic Data Story (DS), an online interactive resource that allows the public to visualize the October 14, 2023 annular solar eclipse from any location around the world, with a focus on North America. This resource is available online at: https://projects.cosmicds.cfa.harvard.edu/annular-eclipse-2023/. During the week of October 6-October 15, the Annular Eclipse DS received 2,000 views. Unless a user opted out of collection of evaluation data, we recorded the number of preset and user-selected locations they viewed and their responses to a multiple-choice map quiz. The group of users we received this data from are called the “evaluation cohort.” The user-selected locations were distributed across the entire US and beyond. On average, users in the evaluation cohort viewed the annular solar eclipse from 5 different locations. Within the evaluation cohort, 70% of users who attempted the map quiz arrived at the correct answer within two guesses.

1. Introduction

Cosmic Data Stories (CosmicDS), part of NASA’s Science Activation program, are online experiences that allow the public to engage interactively with NASA imagery and data. CosmicDS are built using research-grade, open-source visualization tools, including WorldWide Telescope and glue, but provide a scaffolded learning experience within a user-friendly interface. On October 14, 2023, parts of North America experienced an annular solar eclipse. Because the Moon doesn't orbit the Earth in a perfect circle, solar eclipses sometimes happen when the Moon is farther away from Earth and appears smaller. In this case, the Moon doesn't cover the entire face of the Sun. During the eclipse we can still see a bright ring of light around the Moon, sometimes called the "Ring of Fire." This is called an annular Eclipse. The CosmicDS team created an Annular Eclipse Data Story (DS) to support public understanding of the October 14, 2023 event.

2. Annular Eclipse Data Story

The Annular Eclipse DS, released on October 6, 2023, allows users to view what the October 2023 annular solar eclipse would look like from anywhere. Figure 1, Figure 2, and Figure 3 show how users could view the eclipse from pre-set locations across the US or choose any location around the world (although they would have found that the Sun was below the horizon if they chose locations outside of the Americas). To encourage exploration, we added a multiple-choice quiz, where we drew three possible paths on a map. The user had to identify which of the three choices was the path of the annular solar eclipse. Figure 4 shows informational text that provided additional details on the cause of eclipses and the difference between annular and total solar eclipses. Figure 5 shows a video that guided the user through the interface features.

This resource is available online at: https://projects.cosmicds.cfa.harvard.edu/annular-eclipse-2023/ on desktop platforms including Windows, MacOS, and Linux, and mobile platforms including Android and iOS. The DS works on all browsers including Chrome, Firefox, and Safari, but it was tested most extensively (and so would behave most reliably) on Chrome.

The following figures taken from the Annular Eclipse DS show key components of the resource.

Screenshot from the Annular EclipseDS showing the view of the October 14th eclipse from Albuquerque, with the Moon overlapping the Sun against a dark background. Multiple cities are marked in blue across brightly colored map of the US. The location of Albuquerque is marked in red on the map. — **Figure 1**
The default view shows the progression of the annular solar eclipse from Albuquerque, NM, USA. The bottom slider advances time, so the user can see how the view changes from that location, over the course of a few hours. At any given moment, the percentage of the Sun eclipsed by the Moon is displayed.
The user can choose any of the other preset locations on the map to see how the view of the eclipse will differ.

Screenshot from the Annular EclipseDS showing the view of the October 14th eclipse from Albuquerque in "horizon mode." The Sun and Moon are shown on a blue sky rising above a dark green horizon. A grid on the sky shows the altitude and azimuth of the objects and the direction East is marked with a letter E. — **Figure 2**
An alternate “horizon” view allows the user to see how the Sun and Moon travel in the sky at a particular location while the Moon is also approaching the Sun during the annular solar eclipse.

Screenshot from the Annular EclipseDS showing an alternate map that allows the user to choose any location around the world. The map is displaying the view of the eclipse from the location of the Harvard College Observatory in Cambridge, MA. — **Figure 3**
An unconstrained map allows the user to select any location in the world to view the annular solar eclipse from.
A “Share this view” button allows the user to create a URL that opens the DS showing the view from a specific location. This is a great feature for venues hosting eclipse-watch events, so their visitors can preview what to expect from their location.
If a user’s location services are enabled on their device, they can use the “Show view from this location” button to display what the eclipse will look like where they are without having to hunt for their location within the map interface.

Screenshot from the Annular EclipseDS showing informational text that includes multiple FAQs about eclipses. — **Figure 4**
Informational text answers frequently asked questions about solar eclipses and the difference between an annular and total eclipse.

Screenshot from the Annular EclipseDS showing the user guide video that accompanies the activity — **Figure 5**
A video guide shows the user how to use all the different components of the interface.

3. Impact

CosmicDS is part of the NASA Science Activation (SciAct) program, which “connects diverse learners of all ages with science in ways that activate minds and promote a deeper understanding of our world and beyond.” Each SciAct project works with a project evaluator to ensure that our work contributes in a meaningful way to the SciAct program’s overall objectives. For the Annular Eclipse DS, our project evaluator collected data to investigate which features helped to promote engagement with the activity. This data is being used to inform development of a similar DS for the April 8, 2024 total solar eclipse.

In particular, the evaluation sought to answer these questions:

To what extent do users who interact with the Annular Eclipse DS demonstrate an understanding of the path of the eclipse?
To what extent do users who interact with the Annular Eclipse DS demonstrate an interest in the annular solar eclipse beyond exploring the initial view in Albuquerque, NM, USA?

The Annular Eclipse DS provided users with opportunities to engage with NASA science. Users were first introduced to science content about eclipses in the opening view, where they could observe and explore how the view of the annular solar eclipse changes over time in Albuquerque, NM, USA (Figure 1). Users were invited to further explore the path of the eclipse by playing a game to guess the path across the United States by first exploring data from several “preset” cities across the country and then choosing the correct path from one of three options (Figure 3). In addition to information about the path of the eclipse, users could learn more about how the shape of the Moon’s orbit sometimes leads to annular solar eclipses (Figure 5), or how the percentage of the Sun that is covered decreases the farther away you are from the path of annularity.

The Annular Eclipse DS interactive also provided opportunities to inspire users’ interest in STEM. Users could explore cities all over the country (and the world) to watch how the eclipse changed over time at their chosen location (Figure 3). People are naturally curious about what happens at their home, or that of friends and family, so we expected that this would be a popular component of the Data Story and one that would spark interest to continue interacting with the content.

We collected general analytics data, counting the overall number of page views and engagement times for the Annular Eclipse DS, as well as more specific evaluation data regarding how many pre-set cities vs. user-selected locations were viewed by the user, and whether they entered any choices for the map quiz. The analytics data showed that the Annular Eclipse DS was viewed approximately 2,000 times in October 2023, with usage concentrated between October 6, the day of the release of the activity, to October 15, the day after the annular solar eclipse, and had an average viewing time of 1 minute each. Combined with the additional evaluation data, we found that even this brief interaction led to meaningful engagement with the content.

Visitors to the Annular Eclipse DS site had the option to opt out of data collection, and 375 users in October 2023 consented to having evaluation data recorded. We refer to them as the “evaluation cohort.” Within the evaluation cohort, 97% of users did more than the “bare minimum” and viewed the annular solar eclipse from locations other than the default of Albuquerque, NM, USA. Within the evaluation cohort, 70% of users viewed the eclipse from at least one user-selected location, while 44% of the evaluation cohort viewed pre-set locations other than Albuquerque. Many users used both modes of selecting locations besides Albuquerque. For privacy reasons, we did not store any locations that were specified using the “view from my location” button, so if a user only used this feature, they were not counted in our data collection. However, if an evaluation cohort user picked their own location from the map interface, we did not exclude this data, as there was no way to know if the selected latitude/longitude corresponded to the user’s actual location. Users who viewed the eclipse from user-selected locations viewed an average of 4.0 locations each. Users who viewed the eclipse from pre-set locations beyond Albuquerque viewed an average of 2.6 additional locations. Overall, users in the evaluation cohort viewed an average of 4.0 additional locations beyond the default of Albuquerque.

From the release of the DS on October 6th until October 13th, the day before the annular solar eclipse, 30% of users in the evaluation cohort attempted the map quiz. On the day of the eclipse itself, only 6% of users in the evaluation cohort attempted the map quiz, possibly because by that point, they already knew what was going to happen. Of the users who attempted the map quiz, 97% arrived at the correct answer, with 70% getting the correct answer within 2 attempts. Of the users who responded to the map quiz, 42% made 1 attempt to answer, 21% made 2 attempts, and 37% made 3 or more attempts.

Figure 6 shows the distribution of user-selected locations chosen by the evaluation cohort across North and Central America. We expect that many users in the evaluation cohort chose locations near their homes, as that is what people are naturally drawn to do, so we believe that this map is a good representation of the overall user-distribution for the Annular Eclipse DS. Locations around the world were also chosen but are not displayed in this map. Some locations are in the ocean. We are not sure if those were deliberate choices or if they were accidental clicks when scrolling through the map interface. The largest concentration of user-selected locations were in the Northeast, Texas, California, and the Southeast.

Map of North America with red dots scattered across, showing locations selected from the map by the evaluation cohort of Annular EclipseDS users. — **Figure 6**
Within the Annular Eclipse DS evaluation cohort (N=375), 70% used the free-choice location selector. The red markers on this map show the locations chosen by the these 271 users. In total, 1075 locations around the world were viewed by this cohort.

4. Conclusion

Despite being available for only a brief one-week window before the October annular solar eclipse, there was broad usage of the Annular Eclipse DS across the entire US, with 2,000 page views and active engagement from users to view the eclipse from multiple locations beyond the default. Other NASA Science Activation projects that are developing outreach programs for the April 2024 total solar eclipse have expressed interest in a Total Solar Eclipse DS with features drawn from the Annular Eclipse DS. Since the technical software components have already been developed, we plan to release the Total Solar Eclipse DS with a much longer lead time prior to the April eclipse, which we expect will facilitate reaching a larger audience. We will also release a companion educator guide that suggests investigation activities for learners of different ages using the Total Solar Eclipse DS.

Acknowledgments

We are grateful to Peter Williams for his guidance and support with WorldWide Telescope open-source development and to the NASA Science Activation program for supporting development and helping to disseminate this activity.

The material contained in this product is based upon work supported by NASA under cooperative agreement award No. 80NSSC21M0002. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Aeronautics and Space Administration.