This image shows asteroid 2015 VA108, one of the active asteroids spotted by volunteers from the Active Asteroids Citizen Science project. The object, indicated by the green arrow, orbits entirely within the Asteroid Belt between Mars and Jupiter, but sports a tail like a comet.Colin Orion Chandler/University of Washington
Not all asteroids are alike. Some of them, known as "active" asteroids, sport comet-like tails of gas and dust. Studying active asteroids could reveal clues to how the solar system formed and how Earth became a water-bearing oasis for life. They may also aid future space missions.
Active asteroids are also rare. But now scientists have 15 new ones to study. They were spotted by Active Asteroids Citizen Science, a partnership between NASA, the citizen science platform Zooniverse, astronomers and thousands of citizen scientist volunteers. The team announced its discoveries - among the first since the initiative was formed in 2021 - in a paper published March 15 in The Astronomical Journal.
"The collective effort of our volunteers has expanded our understanding of the solar system," said project founder and lead author Colin Orion Chandler, a LINCC Frameworks project scientist at the University of Washington's DiRAC Institute. "The discoveries made by this diverse group of individuals highlight the importance of engaging the public in scientific endeavors."
Around 8,300 volunteers combed through 430,000 images of known asteroids, looking for comet tails or other signatures of active asteroids. The images had been taken by the Victor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile. After searching for additional archival images of each candidate from the Active Asteroids project, the team discovered evidence of tails on more than a dozen objects. Some are in the Asteroid Belt, but others reside closer to Jupiter or wander the outer solar system.
"For an amateur astronomer like me it's a dream come true," said co-author Virgilio Gonano, an Active Asteroids volunteer in Udine, Italy. "Congratulations to all the staff and the friends that also check the images!"
Asteroids can become active due to impacts from other asteroids or by spinning so fast that they eject material off into space. Studying these objects is crucial for scientists to answer pressing questions about the formation and evolution of the solar system, including the origins of water here on Earth. Additionally, active asteroids may be valuable resources for future space exploration missions, because the same ices that are responsible for the comet-like tails could also be critical resources, such as the basis of rocket fuel or even breathable air.
Identifying active asteroids also helps scientists learn more about how often tail-generating events occur and help them understand asteroid behavior - insights that in turn can inform the design of future asteroid deflection endeavors like NASA's recent DART mission.
"I have been a member of the Active Asteroids team since its first batch of data. And to say that this project has become a significant part of my life is an understatement," said co-author Tiffany Shaw-Diaz, an Active Asteroids volunteer who lives in Dayton, Ohio. "I look forward to classifying subjects each day, as long as time or health permits, and I am beyond honored to work with such esteemed scientists on a regular basis."
These efforts complement upcoming missions to rapidly identify solar system objects, such as the Legacy Survey of Space and Time based at the Vera C. Rubin Observatory in Chile, which many UW scientists are part of. And with its recent successes the Active Asteroids Citizen Science team will keep up the search for tails on asteroids near and far, including in the upcoming Rubin data, according to Chandler.
"This project not only furthers our knowledge of celestial bodies but also demonstrates the potential of citizen science in advancing cutting-edge research. Nine of the authors on this paper are citizen scientists," said Chandler. "The success of this initiative reaffirms the importance of collaborative efforts in exploring the mysteries of the cosmos."
Active Asteroids is accepting volunteers for its ongoing work: https://activeasteroids.net/
The research was funded by NASA and the National Science Foundation.
