Citizen scientists make cosmic discoveries with a global telescope network

In January in Monterrey, Mexico, Iván Venzor was one of only a dozen people in the world to glimpse a potential Jupiter-sized planet crossing in front of a distant star.

It happened too fast to see by eye — just a seconds-long flicker of light — but Venzor’s backyard telescope recorded the data, allowing him to verify the event with researchers. “I’m having dinner with my family, and I’m trying to discover a new kind of planet from a few meters outside,” says Venzor, a hobby astronomer. “It’s effortless.”

Venzor’s telescope is part of a growing, global network enabling enthusiasts such as himself to contribute to astronomical research. Made up of over 15,000 small, Wi-Fi–enabled telescopes produced by the French company Unistellar, the network spans six continents and has helped discover hundreds of asteroids, comets and exoplanets. The discoveries rely on occultation — when a sizable object such as an asteroid or planet briefly blocks the light of a star. By measuring the duration of these blockages from multiple locations, astronomers can determine the object’s size, shape and trajectory.

The network “is the coolest citizen science project I’ve ever seen,” says Jon Vandegriff, a space physics data scientist at Johns Hopkins Applied Physics Laboratory in Laurel, Md.

It has allowed researchers to refine predictions for the orbits of asteroids, contribute to exoplanet studies and even observe major space missions. In 2022, when NASA intentionally redirected an asteroid by crashing a spacecraft into it, the network helped track the debris from the collision.

But the telescopes can cost up to $4,000 dollars each, making them inaccessible to many people. So Unistellar and nonprofits including Astronomers Without Borders have gifted telescopes to universities and astronomy clubs around the world to expand the network’s reach.  

For those communities, the ability to contribute to space science is transformative.

Marcelo Souza, an astrophysicist at Universidade Estadual do Norte Fluminense Darcy Ribeiro in Rio de Janeiro, received a free telescope for his astronomy club last year. “When we received it, everything changed,” Souza says. The instrument has become a key tool for teaching, research and astronomy outreach. 

In Armenia, an astronomy club run by space engineer Vachik Khachatryan and his brother, Mher, has used its partially-donated telescope at events for over 2,000 children. Vachik even brought it out at his wedding.

For those interested in contributing to research, Unistellar distributes a list of transitory cosmic objects that can be seen in different locations each month. Once an observer selects their object of interest, they can press a button that directs an app to point the telescope at the target location and record a video of the passing object. Observers can also use the telescope to take still photos of their favorite nebulae and galaxies.

At a meeting of the American Geophysical Union in December, Unistellar’s Chief Scientific Officer Frank Marchis and collaborators reported that the network successfully detected 136 asteroids. A forthcoming paper will detail the discovery of a rare binary asteroid — two space rocks orbiting each other. Meanwhile, a partnership with NASA is helping to refine the orbits of around 20 exoplanets.

The team’s next frontier is using machine learning to minimize false observations caused by clouds or satellites. And in April, 50 observers will receive hardware prototypes that will allow researchers to remotely operate the telescopes, eliminating user error during important transits.

Marchis, who is also a planetary astronomer at the SETI Institute in Mountain View, Calif., wants to scale up the network by expanding participation in underrepresented regions such as Africa, central Asia and South America. That would be a boon for researchers and hobbyists alike.

“On your own, you can do only so much” in astronomy, Venzor says. By working together, “you are feeling part of something greater.”