Scientists Pinpoint When Jupiter Was Born, Unlocking a 4.5-Billion-Year-Old Mystery
Jupiter’s origin has long puzzled astronomers, but a groundbreaking study by researchers from Nagoya University, Japan, and the Italian National Institute for Astrophysics (INAF) has finally revealed the answer. Their work shows that Jupiter’s rapid growth about 4.5 billion years ago triggered massive cosmic collisions, leaving behind tiny molten rock droplets known as chondrules — preserved inside meteorites that still reach Earth today.
🌌 Jupiter’s Gravity and Violent Cosmic Collisions
As Jupiter ballooned into a gas giant, its immense gravitational pull disturbed countless rocky and icy bodies called planetesimals. These disturbances caused high-speed crashes so intense that rock and dust melted into glowing droplets. Over time, these droplets cooled into spherical particles — the mysterious chondrules scientists find embedded in meteorites.
“When planetesimals smashed into each other, water instantly vaporized into steam, breaking molten silicate into the droplets we now see,” explained Professor Sin-iti Sirono of Nagoya University. This natural chain reaction perfectly matches what scientists observe in meteorites today, solving a decades-old enigma.
🪐 Chondrules: Time Capsules From the Birth of the Solar System
Chondrules — usually 0.1 to 2 millimeters wide — are like frozen records of planet formation. Formed in the fiery chaos of early solar collisions, they were later incorporated into asteroids. Billions of years afterward, fragments of those asteroids crash-landed on Earth, bringing clues about the very beginnings of our planetary system.
Using computer simulations, scientists demonstrated that Jupiter’s early growth sparked a surge of collisions, producing abundant chondrules. Their findings reveal that Jupiter’s birth coincided with the peak production of chondrules around 1.8 million years after the solar system’s origin.
📅 Dating the Birth of Jupiter
The team’s model not only confirms when Jupiter was born but also explains why meteorites contain chondrules of varying ages. The study suggests that other giant planets like Saturn may have triggered additional rounds of collisions and droplet formation when they formed, adding new layers to the cosmic timeline.
According to co-lead author Dr. Diego Turrini (INAF), “Our simulations perfectly match meteorite evidence and confirm that Jupiter’s massive growth directly shaped the early solar system.”
🌠 A Window Into Other Planetary Systems
This discovery does more than solve Jupiter’s mystery. It suggests that violent planet-building events may also occur around stars beyond our solar system. By studying chondrules of different ages, scientists can now trace the birth order of planets and uncover how worlds like ours — and perhaps distant alien systems — came to be.
Reference: Scientific Reports, “Chondrule formation by collisions of planetesimals containing volatiles triggered by Jupiter’s formation” by Sin-iti Sirono & Diego Turrini, August 2025.
