Mystery from beyond: 3I/ATLAS fires a 10,000-km Jet towards the Sun in dazzling display

In a breathtaking glimpse into the cosmos, astronomers have captured detailed new images of the interstellar object 3I/ATLAS, revealing a powerful jet of gas and dust blasting directly toward the Sun. The discovery, announced on October 15 via The Astronomer’s Telegram, deepens scientific fascination with this rare celestial visitor — only the third interstellar object ever detected passing through our solar system. 

The newly processed image, taken on August 2 by the Two-meter Twin Telescope (TTT) at Spain’s Teide Observatory, is composed of 159 separate exposures of 50 seconds each. It shows a dense black nucleus — the comet’s icy core — encircled by a glowing white halo known as the coma. Within the halo, astronomers identified a striking fan-shaped jet highlighted in purple, pointing directly sunward. 

While fringe theories have speculated that 3I/ATLAS might be an alien spacecraft, scientists say the evidence overwhelmingly supports a natural explanation. “Jets are pointing to the sunward direction and the comet’s tail in the anti-solar direction,” explained Miquel Serra-Ricart, astrophysicist at Teide Observatory, in comments reported by Live Science. He added that the phenomenon is “entirely natural,” driven by uneven heating as the object nears the Sun — a process that causes trapped volatile gases beneath its surface to erupt like geysers. 

Classic cometary outburst 

The outburst observed from 3I/ATLAS is a textbook example of cometary jet activity, a hallmark of icy bodies traveling close to stars. As the comet’s surface warms, its ices sublimate — transforming directly from solid to gas. When pressure builds under weak surface regions, it erupts explosively, expelling dust and gas thousands of kilometers into space. 

As the nucleus rotates, the jet expands into a broad sun-facing plume, resembling patterns seen in Comet NEOWISE during its spectacular 2020 appearance. Some of this material joins the bright coma around the nucleus, while solar radiation drives other particles outward, forming the tail that extends in the opposite direction of the Sun. 

Serra-Ricart estimates that the current jet from 3I/ATLAS may stretch nearly 10,000 km from its surface. Analysis indicates that it contains primarily dust and carbon dioxide, findings that align with earlier readings from the James Webb Space Telescope in August. 

A fleeting visitor  

3I/ATLAS is now completing its close approach to the Sun. After passing near Mars on October 3, it is expected to reach perihelion — its closest point to the Sun — on October 29. For now, it remains hidden behind the Sun, but astronomers anticipate its reappearance in mid-November, when they will study how its jet and tail evolve as it moves away. 

This discovery marks another milestone in the study of interstellar objects, following the groundbreaking detections of ‘Oumuamua in 2017 and 2I/Borisov in 2019. Each has offered fresh insights into the nature and behaviour of bodies formed beyond our solar system. 

Discovered in late June and confirmed by NASA in early July, 3I/ATLAS is believed to have originated in a distant, ancient star system. Estimated to measure between 5 and 11 km across, it is the largest and possibly the oldest interstellar object ever observed — a cosmic relic that may predate the formation of our Sun by billions of years.