Astronomers around the globe are on high alert after detecting a massive interstellar object — Comet 3I ATLAS — racing through our solar system at an astonishing 210,000 kilometers per hour (130,000 mph).
Discovered on July 1, 2025, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Chile, the comet has quickly become a focal point of international scientific interest for one extraordinary reason: it originated from beyond our solar system.
This makes 3I ATLAS only the third confirmed interstellar visitor, following the mysterious cigar-shaped ‘Oumuamua in 2017 and the comet 2I Borisov in 2019.
However, unlike its predecessors, 3I ATLAS is much larger — measuring nearly 11 kilometers (7 miles) across — making it easier to observe and analyze.
What has stunned scientists most is the comet’s unusual behavior. Unlike typical comets that maintain a consistent color, 3I ATLAS changes hues — glowing green, blue, or even orange as sunlight interacts with its icy surface.
Researchers suggest this indicates the presence of rare, exotic molecules not commonly found in comets native to our solar system.
“These color variations give us a window into the chemical diversity of other star systems,” said Dr. Lucia Ferran, an astrophysicist with the European Space Agency (ESA). “It’s like studying a frozen relic from a different galaxy.”
According to initial studies, 3I ATLAS may be around 7 billion years old, predating the birth of our solar system by almost 3 billion years.
Astronomers believe it formed around a long-dead star before being ejected into interstellar space, where it has wandered for billions of years — a true cosmic time capsule from an ancient era of star formation.
The European Space Agency (ESA) has mobilized several missions to monitor the object. Both the ExoMars Trace Gas Orbiter and Mars Express spacecraft have redirected their cameras to capture images as 3I ATLAS passed approximately 30 million kilometers from Mars.
Scientists hope this data will reveal critical insights into its composition, structure, and trajectory.
The discovery has also reignited enthusiasm for ESA’s upcoming Comet Interceptor Mission, scheduled to launch in 2029.
The spacecraft will wait in deep space, ready to intercept and study future interstellar visitors like 3I ATLAS.
Though 3I ATLAS poses no threat to Earth, its arrival serves as a powerful reminder of the vast, interconnected nature of the universe.
“This is not science fiction,” said Dr. Ferran. “Objects like 3I ATLAS remind us that we’re part of a much larger cosmic story — one that stretches far beyond our solar system.”
As astronomers continue to study this remarkable visitor, 3I ATLAS offers humanity a rare glimpse into the deep history of the galaxy, a frozen messenger from a distant past that survived eons of interstellar travel to tell its story.
