Skywarden: 14 years of citizen science

Abstract

Skywarden (Taivaanvahti) observation system provides a platform for gathering information of celestial phenomena. Nearly half of the observation reports are related to objects within planetary science. These include the planets, exoplanet transits, asteroids, comets, meteor showers, fireballs and eclipses. During its 14 years of operation, Skywarden has proven to be an efficient way of communicating space-related phenomena to the public.   

1. Introduction

Citizen science has been a rising discussion topic in the scientific world during the recent decade. Many projects have already involved volunteers making observations and participating in analysis.

In Finland, the Ursa Astronomical Association has developed and maintained observation system called Skywarden (Taivaanvahti, www.taivaanvahti.fi) since 2011 [1]. The gathered dataset consists of more than 120 000 observations contributed by over 20 000 individual users.    

2. Observed phenomena

The amateur astronomical community in Finland is not only interested in astronomical phenomena but has a long history of promoting observations of atmospheric optics [1]. The reports received by Skywarden cover phenomena from the ground level (storms and atmospheric halos [5]) to distant gamma ray bursts.  45% of the gathered observation material is related to observation targets within our solar system. [Table 1]

2.1 Eclipses

Solar and lunar eclipses are often highlighted by the media and provide easy, but rare, observable events. Skywarden’s eclipse observation theme covers total, partial and annular eclipses. A negative eclipse observation indicates that the location was clouded out.

Table 1: The number of observations sent to different categories in Skywarden, 2011-2025

Category	Number of observations
Atmospheric halos	31 800
Solar system objects	21 300
Fireballs	20 400
Northern lights	15 145
Atmospheric optics, excl. halos	11 200
Deep space	8 400
Rare clouds	8 200
Storms	4 300
Eclipses	1 400

 

2.2 Solar system objects

Of the solar system observations, the Sun and the Moon are the most popular observation targets covering 37% of the category’s material. The observation program also covers planets, comets (14%), asteroids, meteor storms and satellites.

2.3 Fireballs

Skywarden collaborates closely with the Finnish Fireball Network in collecting fireball cases. It provides tools to gather eyewitness reports of fireballs including height, direction, angle and sound information. The approach provides a fast and easy way of mapping out where individual bolides have been observed.

3. Open data and my data

Information sent into Skywarden serves many purposes. Most important of them is the user’s need to communicate achievements, gain visibility and participate in the research. All data gathered is publicly available. Only sensitive parts like contact information remain hidden. The observers receive a modification link, which gives them full control on the sent material.  In addition to the main user interface, information is made available through open Application Programmable Interfaces (API) in several computer readable formats. [2,3]

4. Data processing and quality

Information is sent in by using web observation form dedicated to each observation topic. [Figure 1].

Figure 1: Skywarden’s solar system observation form contains fields for the observation time and -location, observer contact information, description text, images and detailed identifications.

The quality of the incoming data is pre-analyzed by using AI scoring and then checked by the moderation team. Information needed for research, like UT timestamps and coordinates, are set automatically by the system if found missing. Observations belonging to the same event are grouped together and given a shared display id.

5. Observation supporting features

Skywarden maintains an online map of available dark observation locations. Each of these sites contain a description, coordinates and an address, plus additional listed features like visibility towards different directions. This feature raises awareness of the light pollution problem and instructs city-dwellers locations of nearby observations sites without excess lighting.                                      

Skywarden’s user interface contains basic descriptions of the observed phenomena. Together with the specialists’ help, this shared information deepens the learning experience of the observer.

6. Summary and Conclusions

Skywarden provides tools for running future citizen collaboration campaigns [3,4,6]. Unlike many sky-related citizen science observation campaigns, it combines different phenomena under one single platform and publishes observation contents for open research.

During the 14 years of operation, Skywarden has established a position as a reliable source of information for news media. Suddenly occurring phenomena like fireballs or rocket launches can cause worries in citizens. By providing science-based information of the observed phenomena, we do our share in increasing trust and stability. 

Acknowledgements

The authors wish to thank Ursa Astronomical Association for funding the development and maintenance of the Skywarden observation system. We thank the members of the Finnish Fireball Network of Ursa for fruitful collaboration. Creation and presentation of this abstract has been supported by the Research Council of Finland grant 365202.

References

[1] Karttunen, H.: Ursan historia, Tähtitieteellinen yhdistys Ursa ry. 1921–2021, ISBN 978-952-5985-98-6 

[2] Bruus, E.: Skywarden’s search interface (API): https://www.taivaanvahti.fi/app/docs/interface/output_interface_en.html

[3] Grandin, M., Bruus, E., Ledvina, V. E., Partamies, N., Barthelemy, M., Martinis, C., Dayton-Oxland, R., Gallardo-Lacourt, B., Nishimura, Y., Herlingshaw, K., Thomas, N., Karvinen, E., Lach, D., Spijkers, M., and Bergstrand, C.: The Gannon Storm: citizen science observations during the geomagnetic superstorm of 10 May 2024, Geosci. Commun., 7, 297–316, https://doi.org/10.5194/gc-7-297-2024, 2024.

[4] Palmroth M., Grandin M., Helin M., Koski P., Oksanen A., Glad M. A., et al. (2020). Citizen scientists discover a new auroral form: Dunes provide insight into the upper atmosphere. AGU Advances, 1, e2019AV000133.

[5] Moilanen, J. & Gritsevich, M. (2022). Light scattering by airborne ice crystals – An inventory of atmospheric halos. Journal of Quantitative Spectroscopy and Radiative Transfer. 290. 108313. 10.1016/j.jqsrt.2022.108313.

[6] Nishimura, Y., Bruus, E., Karvinen, E., Martinis, C. R., Dyer, A., Kangas, L., et al. (2022). Interaction between proton aurora and stable auroral red arcs unveiled by citizen scientist photographs. Journal of Geophysical Research: Space Physics, 127, e2022JA030570.