A new image from the Hubble Telescope has revealed the clearest glimpse yet of an interstellar visitor zipping through our solar system. The comet, named 3I/ATLAS, came from beyond our solar system and was observed on July 21 when it was 277 million miles away from Earth.
The object’s speed of 130,000 miles per hour makes it the fastest known interstellar visitor to ever be observed in our solar system. Scientists estimate that 3I/ATLAS has been traveling through interstellar space for billions of years, accumulating momentum and increasing its velocity.
This comet is remarkable due to its velocity, which is useful in predicting properties such as age and composition. The discovery of 3I/ATLAS was incredibly fortuitous for recent doctoral student Matthew Hopkins, who had just finished his work on predicting future interstellar object discoveries.
The comet’s size is uncertain but could be anywhere from 1,000 feet to 3.5 miles in diameter. It is expected to remain visible through September before passing too close to the sun to be spotted again until early December.
While scientists are eager to learn more about 3I/ATLAS, big questions remain unanswered, including its origin. The comet appears to behave like comets from our solar system but its speed suggests it’s a visitor from another solar system in our galaxy.
With the Vera C. Rubin Observatory, astronomers now have powerful sky survey capabilities that can spot small, faint and distant objects. Hopkins estimates that this telescope could spy anywhere between five and 50 interstellar objects over the next 10 years, potentially shedding more light on these mysterious visitors.
Source: https://edition.cnn.com/2025/08/07/science/interstellar-comet-3iatlas-hubble-image