NASA Activates Planetary Defense Network for Mysterious Interstellar Comet 3I/ATLAS
NASA and its global partners have quietly activated planetary defense protocols to monitor the interstellar comet 3I/ATLAS, a Manhattan-sized object exhibiting unprecedented behaviors since its discovery on July 1, 2025, by the ATLAS telescope in Chile. This is the first time an interstellar object has been formally included in a planetary defense observation campaign coordinated by the UN-backed International Asteroid Warning Network (IAWN).
Historic Monitoring Campaign
The IAWN announced an unprecedented comet astrometry campaign running from November 27, 2025, to January 27, 2026, focusing exclusively on 3I/ATLAS. The campaign aims to improve precise comet tracking techniques and test planetary defense readiness for small bodies exhibiting complex behaviors. The monitoring initiative seeks to collect extensive data on the comet’s trajectory, gas emissions, dust, and physical properties to better understand this rare interstellar visitor.
Unprecedented Anomalies Challenge Scientists
3I/ATLAS has demonstrated several unusual traits distinguishing it from typical comets. Notably, it displayed an "anti-tail"—a dust stream directed toward the Sun, contrary to common comet tails that point away due to solar radiation pressure. Intriguingly, this anti-tail later reversed direction, adopting the typical orientation observed in comets.
Spectroscopic studies revealed the emission of nickel tetracarbonyl, a compound previously identified only in human industrial processes and alien to natural comet compositions. The comet emits around four grams of nickel per second without the usual accompanying iron, baffling researchers.
NASA spacecraft Europa Clipper and ESA’s Hera mission are positioned to possibly sample the comet’s ion tail as it passes nearby between October 25 and November 6, offering a unique chance to study material from beyond our solar system.
Scientific Debate on Its Origin
While mainstream scientists classify 3I/ATLAS as a natural comet and point to the detection of water, carbon dioxide, and other typical cometary compounds, some researchers question its origin. Harvard astrophysicist Avi Loeb has suggested that its trajectory, aligned closely to Earth’s orbital plane and its unusual chemical emissions and tail behavior, raise the possibility of an artificial origin or extraterrestrial technology presence.
However, European Space Agency’s Head of Planetary Defence, Richard Moissl, and other experts report no signs pointing towards non-natural origins in existing observational data. The comet travels at an extraordinary speed of about 210,000 km/h and is estimated to weigh approximately 33 billion tons, measuring 3-7 miles (5-11 km) wide.
What’s Next?
3I/ATLAS will reach its perihelion, the closest point to the Sun, on October 29, 2025, at about 1.4 astronomical units (AU). After passing perihelion, it will be obscured by the Sun until early December, when it will reappear for further observation before departing the solar system permanently. The ongoing observation campaign over the next two months is expected to yield new insights into this enigmatic visitor, improving planetary defense techniques and enriching our understanding of interstellar objects.
This historic campaign marks a new era in planetary defense, turning scientific curiosity and vigilance into a concerted effort to study the unexpected and prepare for any potential implications of interstellar visitors like 3I/ATLAS.