On the night of July 1, 2025, something strange caught the eyes of astronomers using the ATLAS

telescope in Chile—a tiny moving dot, just beyond Jupiter’s orbit. At first, it looked like another
routine find. Maybe an asteroid. Maybe a distant comet. Nothing unusual. But within hours,
that changed. Scientists realized they weren’t looking at a local space rock. This was something
far more rare—a visitor from beyond our Solar System. What they had spotted was an
interstellar object. Now officially named Comet 3I/ATLAS, this icy traveler is only the third
interstellar object ever discovered. And size that could range from 5 to 50 kilometers in
diameter making this the largest interstellar object ever observed.

within days of its detection, it had already become a global sensation.

But, What makes it so special? Well, this new visitor could help solve some of the mysteries left
behind by its two famous predecessors—‘Oumuamua and Comet Borisov.

But first -how do scientists know 3I/ATLAS is truly interstellar? The answer lies in its motion.
Most comets, asteroids, and planets in our solar system follow elliptical orbits governed by the
Sun’s gravity. But it is traveling at about 70 kilometers per second --- that’s twice as fast as Earth
orbits the Sun. And it’s way too fast to be caught by the Sun’s gravity. Any object moving that
quickly can’t be gravitationally bound.--It’s just passing through.

To put that in perspective, the Parker Solar Probe—the fastest spacecraft humans have ever
built—hit 192 kilometers per second after extreme planning and multiple gravity assists. And
even that wouldn’t be fast enough to intercept this comet.

So what makes it a comet rather than just a fast rock? When icy objects approach the Sun, the
heat causes surface ices to vaporize, turning directly into gas. That process creates a glowing
coma, and sometimes even a tail. With 3I/ATLAS, astronomers first noticed a faint fuzziness
around it—almost like a halo. That subtle glow hinted that the surface was reacting to sunlight.
Over 100 follow-up observations from around the world soon confirmed the signs: a visible
coma, and the beginning of a tail. That was enough for the International Astronomical Union to
step in and officially update its name to C/2025 N1, confirming that we were indeed looking at
an active comet.

At the time of discovery, 3I/ATLAS was about 670 million kilometers from Earth, within Jupiter’s
orbit. It was incredibly faint—about 2.5 million times dimmer than the Pole Star. It’s expected to
reach perihelion, the closest point to the Sun, around October 30, at about 206 million
kilometers—just inside Mars’s orbit. However, during this time, it will be on the opposite side of
the Sun from Earth, making direct observation difficult. By early December, it will emerge from
behind the Sun, giving astronomers another window for observation before it dims and recedes
into interstellar space. It will likely remain visible to large telescopes until early 2026, after
which it will fade into the darkness of interstellar space once again.It will also pass relatively
close to Mars—on October 3, 2025. And though it won’t come particularly close to Earth, it will
reach its closest point to us—about 1.8 AU—on December 19- .offering astronomers a rare
chance to monitor this object before, during, and after perihelion.”

Before 3I/ATLAS, only two confirmed interstellar objects had been found. The first, ‘Oumuamua,
was discovered in October 2017. Its trajectory was unmistakably interstellar, but what truly
puzzled scientists was its strange behavior after passing the Sun. It accelerated slightly—without
any visible signs of outgassing—and appeared to have a highly elongated or flattened shape.
This led to wild speculation, including theories that it was an alien probe or light sail. While the
artificial hypothesis was eventually dismissed by most scientists, its physical characteristics
remain unexplained.

Comet Borisov, on the other hand , was discovered in 2019 by amateur astronomer Gennadiy
Borisov. It looked and behaved like a normal comet, with a bright coma, a long tail, and chemical
signatures that included cyanide and carbon-based molecules. Borisov’s detection confirmed
that icy comets can survive long interstellar journeys and appear quite similar to Solar System
comets.

So now, with 3I/ATLAS, we have a third alien object. And already, it looks like a mix of the two.
Some signs of activity, but weak. Some indications of outgassing, but inconsistent. Depending
on which telescope you use—and when you look—you might see a tail, or you might not.

This is what makes interstellar objects so fascinating. They don’t behave the way we expect.
They don’t follow neat rules. And every one of them is a message—one we can barely read—
about how other solar systems are built.

Astronomers are closely monitoring 3I/ATLAS’s brightness, structure, and chemical signatures.

Future comparisons of 3I/ATLAS with other comets, including those from our own Solar System,
will help determine whether planetary systems across the galaxy form similar materials or if
each system is chemically unique. If we detect exotic molecules, it could mean this object
formed under conditions we don’t see here—maybe around a cooler star, or in a different kind
of disk. That’s real insight into how other planetary systems evolve.

And the timing matters. Because we caught this one early, we can track it before, during, and
after perihelion. We can see how the activity changes, what triggers it, and how fast it fades.

This is one of the most direct ways we can investigate the chemistry of alien worlds without
traveling to them.

So, Can we send a probe to intercept it?

Even though we spotted it early, sending a spacecraft after something moving 70 km/s is a huge
challenge. It would take years to build the mission, and we’d still need gravity assists to build up
speed. By then, the object would be long gone.

There have been proposals—like Project Lyra—that suggest ways to chase these objects. Using
solar sails, close flybys of the Sun, or nuclear propulsion. But none of that is off-the-shelf. It
takes funding, time, and planning.

still, the European Space Agency and NASA are planning for the future. Concepts like ESA’s
Comet Interceptor and NASA’s proposed interstellar interceptor missions are being designed to
sit in wait at stable points in space, ready to launch toward a new visitor once detected. The
quick discovery of 3I/ATLAS reinforces the need for such rapid-response capabilities.

Even the question of where it came from is under study. Researchers are simulating its past
trajectory, hoping to trace it back to a region of origin. Its high speed and retrograde motion
suggest it came from the thick disk of the Milky Way, a region populated by some of the galaxy’s
oldest stars. If correct, ATLAS could be over 7 billion years old—older than our Solar System.

It also opens up new theories about how such objects get ejected from their home systems.

As of now, “There’s no evidence suggesting of alien origin.

One question keeps coming up: Why are we seeing these objects now?

The answer isn’t that they just started showing up. It’s that we finally got good at spotting them.

A few decades ago, an object like this would have flown through unnoticed. Space is enormous,
and these things are small, dim, and fast. But modern sky surveys like ATLAS, Pan-STARRS, and
soon the Vera C.

Rubin Observatory, nearing completion in Chile, is expected to revolutionize transient

That increased sample size will be a game-changer. Right now, astronomers are working with
just three confirmed interstellar objects. With more, they can finally build a statistical
understanding—categorizing these objects, estimating their frequency, mapping their origins,
and determining how common certain characteristics are.

. They may be small, cold, and fast—but their journeys tell us something profound about
planetary formation across the galaxy.

So, What story is 3I/ATLAS carrying with it from another star? Drop your thoughts in the
comments—and if you want to keep up with this rare encounter and the ones still to come, hit
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