Ancient Alien Comet 3I/ATLAS Erupts In Stunning Jet Blast As It Hurtles Toward Earth's Neighbourhood

A visitor from another star is tearing through our solar system, hailing from another star. This interstellar comet, named 3I/ATLAS, is putting on a dramatic show. It is ejecting vivid jets and a rich gas cloud, an activity that gives astronomers a rare opportunity to study matter from a distant part of the galaxy.

Every available telescope is now pointed its way. Scientists believe this comet may hold the key to understanding the building blocks of planets, as its strange chemical signature has already challenged conventional wisdom.

A Rare Alien Visitor Reveals Its Nature

Images captured by the Hubble Space Telescope on 21 July 2025 showed a teardrop-shaped cocoon of dust surrounding a solid icy nucleus, the telltale signature of a comet rather than an asteroid. Follow-up observations confirmed that the nucleus is between roughly 440 metres and 5.6 kilometres across. Its size is significant. But its origin from beyond our solar system makes 3I/ATLAS a truly rare sample of ancient, interstellar matter.

Unprecedented Activity: Jets, Coma, and Alien Chemistry

Observations from the James Webb Space Telescope (JWST) in August 2025 delivered a major surprise. The gas cloud surrounding the comet is overwhelmingly made of carbon dioxide (CO₂). Water ice, water vapour, and carbon monoxide (CO) were also present, but the CO₂-to-water ratio was roughly 8:1. That is one of the highest ever recorded for a comet.

Spectroscopy from the Earth-based telescopes added further detail: the emerging coma has weak emission of cyanide (CN), and carbon-chain molecules appear drastically depleted compared with typical solar system comets. Such an unusual chemical signature suggests the comet's nucleus may have been processed under intense cosmic-ray exposure over billions of years, consistent with deep interstellar origins.

International Spacecraft Converge on 3I/ATLAS

Virtually the entire fleet of major solar-system‐observing spacecraft is focusing now on 3I/ATLAS. Probes from NASA and ESA, including the Lucy Spacecraft, MAVEN, Mars Reconnaissance Orbiter (MRO), Psyche Spacecraft, SOHO, STEREO, and the spacecraft of the SPHEREx mission, have all contributed imagery or data as the comet sped past Mars and the Sun.

In October 2025, 3I/ATLAS made its closest approach to Mars, roughly 30 million kilometres, allowing orbiters to capture ultraviolet images of its coma. Weeks later, on 19 November 2025, NASA held a livestreamed event to release the data, after a delay caused by a US government shutdown.

Why This Comet Matters For Cosmic History

Comets from within our solar system carry the chemical fingerprint of the early Sun's environment. 3I/ATLAS, by contrast, provides a direct sample of another star system's composition. Its unusually high CO₂ content and depleted carbon chains could reflect formative conditions unlike our own.

According to a NASA statement, all current observations are consistent with 3I/ATLAS being a comet, not an alien spacecraft, but one with extraordinary scientific value. As NASA scientist Amit Kshatriya put it, 'It looks and behaves like a comet ... but this one came from outside our solar system, which makes it fascinating, exciting, and scientifically very important.'

By 19 December 2025, 3I/ATLAS will make its closest approach to Earth at about 270 million kilometres (170 million miles), a safe distance but close enough for ground- and space-based telescopes to gather more data as it continues its journey back into interstellar space.