3I/ATLAS May Be 7 Billion Years Old

Astronomers spot 3I/ATLAS, an interstellar comet possibly 7 billion years old. It may unlock secrets about ancient galaxies and how stars and planets are born.

What’s the story

An ancient traveler from beyond our solar system just showed up—and it’s blowing scientists’ minds. On July 1, 2025, astronomers using the ATLAS telescope in Chile discovered comet 3I/ATLAS speeding toward the Sun. What’s wild? It might be 7 billion years old—about 3 billion years older than Earth itself. It’s only the third interstellar object ever spotted in our neighborhood, joining the ranks of 1I/’Oumuamua (2017) and 2I/Borisov (2019). This one’s special. Its path through space tells us it came from a far-off corner of our galaxy. Scientists believe it formed near the Milky Way’s thick disk, making it one of the most ancient icy bodies we’ve ever seen, according to the Royal Astronomical Society and University of Oxford.

Ice trail
Comet’s icy body reveals a long cosmic journey

This comet isn’t just old—it’s also icy, which is a clue about where it came from. Scientists at Oxford say 3I/ATLAS is likely rich in water ice because it formed in the cold outer reaches of a thick-disk star system. It was about 420 million miles from the Sun when it was first seen, and it’s already showing activity. As it gets closer to the Sun, it should grow a glowing tail—just like classic comets we’ve seen in our night skies. But unlike them, this one started its journey billions of years ago and traveled across interstellar space to get here. That makes it more than just a pretty sight—it’s like a deep freezer carrying untouched material from before our solar system was born.

Star path
Comet’s route proves it came from ancient stars

What makes 3I/ATLAS different is its steep path through our galaxy. Unlike comets that loop gently around our Sun, this one’s coming in sharp—from above the galactic plane. According to Dr. Matthew Hopkins, who presented his findings at the National Astronomy Meeting in Durham on July 11, 2025, the comet’s route suggests it came from the Milky Way’s thick disk, a place filled with older stars. That gives it an age of nearly 7 billion years. Compared to regular comets like Halley’s—which are about 4.5 billion years old—this one’s practically a time capsule. Only two other interstellar objects have ever been tracked, and neither came from this deep in space.

🛰️ Quick Fact Box

• Discovered: July 1, 2025 (ATLAS Telescope, Chile)
• Estimated Age: ~7 billion years
• Type: Interstellar comet (3rd ever detected)
• Expected Visibility: Late 2025 to early 2026
• Tail Formation: Begins as it nears Sun

Bright tail
Sunlight will soon light up the ancient comet

Here’s where it gets beautiful. As the comet approaches the Sun, it’s expected to burst with energy. The sunlight will heat its icy surface, causing gas and dust to shoot out. This will form a glowing coma and a tail, just like in textbook comet images. According to astronomer Michele Bannister from the University of Canterbury, early data already shows signs that 3I/ATLAS is active. If it continues, it might become visible in the night sky to amateur stargazers by the end of the year. Since it’s possibly bigger than either ‘Oumuamua or Borisov, scientists are hopeful it’ll be one of the brightest and most studied interstellar comets ever seen.

Model test
A PhD student’s model predicted it perfectly

Here’s a real-life “movie plot” moment. Just a week before the discovery, researcher Matthew Hopkins had finished his PhD thesis, which used a model to predict how interstellar objects behave. Then boom—3I/ATLAS is spotted. His model nailed it. Called the Otautahi–Oxford Model, it helped scientists figure out the comet’s origins and path quickly. According to Hopkins, this wasn’t a quiet week as planned: “I woke up to messages like ‘3I!!!!!!!!!!’” The fact that his model aligned so closely with the real data adds a new layer of confidence for future predictions. It could be used to spot other objects like this in coming years.

Rubin ready
New telescope could spot dozens more like 3I

The Vera C. Rubin Observatory in Chile hasn’t even fully started its main operations, and it’s already changing the game. According to Rosemary Dorsey from the University of Helsinki, their simulations using this new telescope suggest it could find 5 to 50 more interstellar objects in the next decade. That’s a huge jump from the three we’ve spotted so far. With Rubin’s ultra-wide sky view, researchers believe some of these future finds might be just as big—or even bigger—than 3I/ATLAS. And who knows? Maybe one will pass even closer to Earth, giving backyard astronomers across India a stunning show.

Milky route
Comet shows us where stars really come from

Using maps of the Milky Way and the comet’s path, researchers have started unlocking the comet’s real journey. They believe it’s traveled in loops across arms of the galaxy we barely know, including the Orion Arm where our solar system lives. It likely passed through gas clouds, star nurseries, and maybe even old supernova zones. Its path isn’t just a route—it’s a record of places we can’t explore in person. This gives astronomers clues about how material from other parts of the galaxy might mix with our solar system. It could even help explain how building blocks for life travel through space.

Life clues
Comet could hint at how life begins in space

Now here’s the exciting part for dreamers and science geeks alike. If 3I/ATLAS has materials from stars older than ours, it might carry organic molecules—the same kind found in early Earth’s environment. That’s important because many scientists think life here might have started with help from comets like this, delivering water and carbon-based compounds. This one might give the clearest proof yet. The gases it releases as it gets closer to the Sun could tell us what it’s made of. If we spot amino acids or other prebiotic molecules, it could totally reshape how we think about life forming across the universe.

First look
Early images already show activity on the surface

Telescopes around the world are already capturing pictures of 3I/ATLAS. And some of them show jets of gas shooting from its surface—a sign that it’s already “waking up” from its long journey. Observatories like the European Southern Observatory and NASA’s IRAM telescope are now focused on tracking its every move. These early images help scientists study how fast the comet is spinning, what kind of material is escaping, and whether the comet’s nucleus (its core) is breaking up. The more they watch, the more they learn—and that means a better understanding of objects that may be older than time itself.

Comet buzz
Astronomy fans across India getting excited

With news spreading fast on WhatsApp groups and Reddit threads, Indian space lovers—from students to retired ISRO engineers—are buzzing about 3I/ATLAS. Observatories in Ladakh and Tamil Nadu have already joined the effort to track it. Kids in Pune are sketching the comet’s path for science projects. Planetariums in Delhi and Bengaluru are planning viewing nights for later this year. This moment feels a bit like the last solar eclipse, where the whole country paused to look up. 3I/ATLAS may be an icy rock, but it’s got everyone dreaming big—and that’s rare in a time when most of us are glued to phones instead of the skies.

Cosmic lesson
Why this ancient comet really matters to us

This isn’t just space stuff—it’s a reminder of how tiny and connected we are. As Chris Lintott of BBC’s The Sky at Night said:

“This is an object from a part of the galaxy we’ve never seen up close before.”
Comet 3I/ATLAS is a chance to learn not just about the stars, but about ourselves—our origins, our curiosity, and our future in space. And guess what? This is just the beginning. Keep an eye on the skies this December. You might just spot something from 7 billion years ago, lighting up your night. Let it spark wonder. Let it make you ask questions. And most of all, let it remind you—we’re all part of something massive and magical.

Also Read – Solar System Visitor 3I/ATLAS Sparks Awe and Wonder
Reference Article –Royal Astronomical Society