Hubble REVEALS Fastest Cosmic Visitor!

A high-resolution image from the Hubble Space Telescope has revealed a dusty coma and faint tail of an interstellar comet, offering the most detailed view yet of this rare cosmic visitor.

At a Glance

Hubble imaged the interstellar comet 3I/ATLAS on July 21, 2025, when it was approximately 277 million miles (3.8 AU) from Earth
The image clearly shows a teardrop-shaped cocoon of dust (coma) and the beginning of a tail extending from the nucleus
Analysis places the comet’s nucleus between about 1,000 feet (320 m) and 3.5 miles (5.6 km) across
3I/ATLAS is traveling at over 130,000 mph (210,000 km/h)—the fastest interstellar object observed to date—and poses no threat to Earth
This marks the third confirmed interstellar object, following 1I/ʻOumuamua (2017) and 2I/Borisov (2019)

Detailed Insights

Hubble’s Capture and Comet Activity

On July 21, 2025, the Hubble Space Telescope imaged 3I/ATLAS from a distance of about 3.8 AU, revealing a clear dust envelope around its nucleus with the faint onset of a tail—features typical of active comets. The teardrop-shaped dust cocoon and tail suggest the comet is outgassing material as it approaches the Sun.

Watch now: Interstellar Visitor is Fastest Comet Ever Recorded · NASA Goddard

Size Estimates and Physical Properties

Scientists estimate the comet’s nucleus lies between roughly 320 meters (1,000 feet) and 5.6 kilometers (3.5 miles) in diameter. These figures reflect the uncertainty caused by the surrounding coma, which obscures the true size of the nucleus.

Trajectory and Speed

3I/ATLAS is moving at speeds exceeding 209,000 km/h (130,000 mph), making it the fastest recorded visitor of its kind. Its hyperbolic path confirms an origin beyond the Solar System, and it presents no danger to Earth.

Context and Scientific Significance

As only the third interstellar object detected so far, 3I/ATLAS enriches our understanding of extrasolar bodies. Its detection and characterization underscore the value of powerful telescopes and sky surveys in identifying such fleeting visitors.