Harvard scientist proposes global network to detect interstellar objects

Friday 30 January 2026 - 14:50

By: Dakir Madiha

Harvard scientist proposes global network to detect interstellar objects

A Harvard astrophysicist has called for a worldwide early-warning system to spot high-speed visitors from beyond our solar system, spurred by unusual traits in the interstellar comet 3I/ATLAS. Discovered in July 2025 as it streaked through our cosmic neighborhood, the comet's peculiarities have prompted fresh scrutiny and innovative detection strategies.

In a new paper co-authored with graduate researcher Oem Trivedi, Avi Loeb outlines the Comprehensive Interstellar Objects Network, or CISON. This layered framework argues that humanity lacks the tools to reliably detect and respond to fast-moving interstellar objects. It envisions three stages: high-cadence sky surveys in both hemispheres for discovery; rapid characterization via moon-based optical interferometry; and selective interception missions for objects with high scientific value or potential risks.

Recent observations amplified the comet's intrigue. On January 22, 2026, NASA's Hubble Space Telescope, in collaboration with the European Space Agency, captured 3I/ATLAS in a rare near-opposition alignment, with Earth positioned almost directly between the sun and the comet—just 0.69 degrees from the Earth-sun axis. Astronomer Man-To Hui of Shanghai Astronomical Observatory, who led the Hubble work, noted such conditions might not recur for decades. Processed images revealed four jets: a prominent anti-tail pointing sunward and three mini-jets spaced 120 degrees apart. NASA's TESS spacecraft also observed the comet from January 15 to 22, measuring its brightness at about magnitude 11.5.

What sets 3I/ATLAS apart are its unprecedented features, including exceptionally high polarization amplitude and extreme negative polarization unseen in any known comet, even compared to prior interstellar visitor 2I/Borisov. Researchers attribute this to the intrinsic optical properties of refractory dust particles rather than fleeting volatile activity. "3I/ATLAS scatters light in a way never seen before in any other comet," the team observed.

Current surveys fall short due to low scanning frequencies, missing rapid interstellar travelers early enough for study. The United Nations International Asteroid Warning Network has tracked 3I/ATLAS since November 2025 in its first planetary defense exercise targeting an interstellar object. The European Space Agency's Comet Interceptor mission, slated for 2029, could target future visitors if timing aligns.