The arrival of 3I/ATLAS, the third interstellar object ever detected passing through our solar system, has sent ripples of excitement through the scientific community. As news broke on July 1st, teams across the globe, including astronomers at Michigan State University (MSU), raced to train their telescopes on this rare celestial visitor. Now, a new scientific paper led by MSU’s Darryl Seligman, an assistant professor in the College of Natural Science, is compiling what’s known so far about this enigmatic object.
3I/ATLAS was discovered by NASA’s Asteroid Terrestrial-impact Last Alert System (ATLAS), a network of four telescopes strategically positioned around the world. These telescopes tirelessly scan the skies, searching for moving objects that could pose a threat to our planet. The discovery highlights the importance of these survays.
The research has been made available on the arXiv preprint server, allowing for rapid dissemination and collaboration within the scientific community. It’s a fast-paced environment, where timing is crucial.
“I heard something about the object before I went to bed, but we didn’t have a lot of information yet,” Seligman explained. “By the time I woke up around 1 a.m., my colleagues…were emailing me that this was likely for real. I started sending messages telling everyone to turn their telescopes to look at this object and started writing the paper to document what we know to date. We have data coming in from across the globe about this object.”
Discovery and Confirmation
Larry Denneau, a member of the ATLAS team, played a crucial role in reviewing and submitting the initial observations. The data came from the European Southern Observatory’s Very Large Telescope in Chile. He described his initial reaction as “cautiously excited,” acknowledging past false alarms. “We have had false alarms in the past about interesting objects, so we know not to get too excited on the first day. But the incoming observations were all consistent, and late that night it looked like we had the real thing.”
Denneau also highlighted the significance of the discovery location: “It is especially gratifying that we found it in the Milky Way in the direction of the galactic center, which is a very challenging place to survey for asteroids because of all the stars in the background. Most other surveys don’t look there.” The discovery speaks to the power of focused observation.
John Tonry, another key member of the ATLAS team from the University of Hawaii, emphasized the reward of their work. “It’s really gratifying every time our hard work surveying the sky discovers something new, and this comet that has been traveling for millions of years from another star system is particularly interesting.”
Karen Meech, faculty chair for the Institute for Astronomy at the University of Hawaii, described the rapid response following the confirmation. “Once 3I/ATLAS was identified as likely interstellar, we mobilized rapidly. We activated observing time on major facilities like the Southern Astrophysical Research Telescope and the Gemini Observatory to capture early, high-quality data and build a foundation for detailed follow-up studies.” Few could have predicted it.
Key Findings About 3I/ATLAS: A Cosmic Summary
While much remains unknown, scientists have already gleaned valuable insights into 3I/ATLAS. Here are some key characteristics:
- Rarity: It’s only the third interstellar object ever detected passing through our solar system.
- Potential Cometary Activity: There are indications it might be emitting gas like a comet, though further confirmation is needed.
- High Velocity: It’s traveling at an astounding speed of 60 kilometers per second (134,000 miles per hour) relative to the Sun.
- Hyperbolic Trajectory: Its orbital path resembles a boomerang or hyperbola, ensuring it will exit our solar system and not return.
- Brightness: It appears to be quite bright, suggesting substantial size or reflectivity.
- Temporary Presence: While its stay is limited, scientists have several months to study it before it departs.
The upcoming observations from the James Webb Space Telescope and the Hubble Space Telescope promise to provide even more detailed information. Scientists hope to determine its precise size, composition, rotation, and how it responds to solar heating. The wait is anticipatory.
Georgia Tech professor James Wray noted the challenges in analyzing the distant object. “We have these images of 3I/ATLAS where it’s not entirely clear and it looks fuzzier than the other stars in the same image,” he says. “But the object is pretty far away and, so, we just don’t know.” The distance creates dificulties.
Seligman’s team is particularly interested in the object’s brightness, as it can reveal insights into the evolution of its coma. They are actively monitoring for any sudden outburst events that could significantly increase its luminosity.
“3I/ATLAS likely contains ices, especially below the surface, and those ices may start to activate as it nears the sun,” Seligman explained. “But until we detect specific gas emissions, like H₂O, CO or CO₂, we can’t say for sure what kinds of ice or how much are there.” This analysis relies on advanced instrumentation.
Inspiration for the Next Generation
The arrival of 3I/ATLAS is not only a boon for established scientists but also an inspiration for the next generation of researchers. Tessa Frincke, a new doctoral student at MSU, sees this as an opportunity to publish her own scientific paper by analyzing data and predicting the object’s future path. “I’ve had to learn a lot quickly, and I was shocked at how many people were involved,” Frincke shared. “Discoveries like this have a domino effect that inspires novel engineering and mission planning.”
Atsuhiro Yaginuma, a fourth-year undergraduate student on Seligman’s team, is considering the audacious possibility of launching a spacecraft to intercept 3I/ATLAS. “The closest approach to Earth will be in December,” Yaginuma explained. “It would require a lot of fuel and a lot of rapid mobilization from people here on Earth. But getting close to an interstellar object could be a once-in-a-lifetime opportunity.”
This spirit of exploration and discovery, however, hinges on continued funding for scientific research. “We can’t continue to do this research and experiment with new ideas from Frincke and Yaginuma without federal funding,” Seligman emphasized.
Seligman and Aster Taylor, a former student and current doctoral candidate, co-wrote an essay highlighting the broader impact of astronomical research: “At a critical moment, given the current congressional discussions on science funding, 3I/ATLAS also reminds us of the broader impact of astronomical research. An example like 3I is particularly important to astronomy—as a science, we are supported almost entirely by government and philanthropic funding.” The need for fundings is clear.
They continued, “The fact that this science is not funded by commercial enterprise indicates that our field does not provide a financial return on investment, but instead responds to the public’s curiosity about the deep questions of the universe: Where did we come from? Are we alone? What else is out there? The curiosity of the public, as expressed by the will of the U.S. Congress and made manifest in the federal budget, is the reason that astronomy exists.” This statement underscores the intrinsic value of exploration.
The excitement surrounding 3I/ATLAS is palpable online. Comments on X.com range from technical discussions of its trajectory to expressions of awe and wonder. “This is what it’s all about!” one user exclaimed. On Facebook, groups dedicated to space exploration are buzzing with discussions and shared images. Even on Instagram, amateur astronomers are posting their own observations of the distant object.
This widespread interest highlights a fundamental tension at the heart of scientific funding: the need to balance practical applications with the pursuit of fundamental knowledge. While commercial enterprises often prioritize research with clear economic benefits, fields like astronomy rely on public support to answer profound questions about our place in the universe. The discovery of 3I/ATLAS serves as a powerful reminder of the importance of nurturing this innate human curiosity and investing in the exploration of the unknown.
Ultimately, the story of 3I/ATLAS is not just about a distant object hurtling through our solar system. It’s a story about the power of human collaboration, the thrill of discovery, and the enduring quest to understand the vast cosmos that surrounds us. It is also about the next generaton.
More information:
Darryl Z. Seligman et al, Discovery and Preliminary Characterization of a Third Interstellar Object: 3I/ATLAS, arXiv (2025). DOI: 10.48550/arxiv.2507.02757