On a February night in 2023, the people of Normandy, France, witnessed something extraordinary. A glowing fireball streaked across the sky, brighter than the stars, accompanied by a sudden flare that lit up the landscape. For most who saw it, the event was a spectacle—one of nature’s dramatic cosmic shows. But for astronomers, it was a rare and scientifically priceless moment: the impact of a small asteroid predicted in advance and tracked from space to the ground.
The asteroid, named 2023 CX1, was no larger than a household appliance. Measuring just 72 centimeters in diameter and weighing around 650 kilograms, it seemed insignificant compared to the mountain-sized space rocks that often capture headlines. Yet its fiery fall revealed something scientists have long suspected but rarely observed with such clarity: even small asteroids can pose unexpected risks when they explode in Earth’s atmosphere.
The Race Against Time
The discovery of 2023 CX1 happened only hours before its arrival. About seven hours before the impact, astronomers detected the asteroid hurtling toward Earth. Among them was Peter Jenniskens, an astronomer at the SETI Institute and NASA Ames Research Center. Realizing the urgency, he quickly contacted his brother in the Netherlands, who stepped outside just in time to witness the fireball streak across the sky.
Meanwhile, astronomers around Europe and beyond scrambled to document the event. Amateur and professional observers alike captured photographs and videos, preserving a detailed record of the asteroid’s fiery demise. This global collaboration provided researchers with the rare chance to study a small asteroid’s impact from detection to aftermath.
A Difficult Hunt for Fallen Stones
The challenge did not end when the fireball faded. Jenniskens joined forces with François Colas of the Paris Observatory, who leads the FRIPON fireball camera network. Along with volunteers from the FRIPON/Vigie-Ciel citizen science program, they set out to recover fragments of the fallen meteorite in Normandy.
Finding meteorites is never easy. Strong winds had scattered the fragments unpredictably, and the atmosphere itself had sorted the stones by size and mass. The team combed fields systematically, scanning for any signs of blackened rock among moss and grass. Their patience was rewarded: Jenniskens himself found a tiny 3-gram fragment, a stone so small it could easily have been overlooked. Today, that fragment is preserved in the Natural History Museum in Paris, a small but invaluable relic of a cosmic visitor.
A Meteorite with a Story
Analysis revealed that the meteorite belonged to a familiar class: ordinary chondrites, specifically a low-iron L-type. These are the most common meteorites found on Earth, and they provide key insights into the early solar system, having remained largely unchanged for billions of years.
But what made 2023 CX1 different was not its composition but the way it broke apart. Witnesses reported a double flare at the end of its descent, an unusually bright flash that hinted at a violent disintegration deep in the atmosphere.
The Sudden Breakup
Most small asteroids break apart gradually as they encounter the thickening layers of Earth’s atmosphere. Energy is released over several kilometers of altitude, creating a long trail of glowing debris. But 2023 CX1 behaved differently.
At an altitude of about 28 kilometers, it disintegrated abruptly, releasing 98% of its kinetic energy in an instant. The result was a concentrated spherical shock wave that spread outward with surprising force. Calculations at NASA Ames Research Center showed that the blast affected an area four times larger than expected for an asteroid of its size.
This sudden release of energy is not just a curiosity. It has profound implications for planetary defense. The closer such explosions occur to the ground, the more devastating their impact can be on populated areas. Even small asteroids, if they hold together until low altitudes, can unleash enough energy to shatter windows, damage buildings, and cause injuries—much like the 2013 Chelyabinsk event in Russia, which sent shockwaves across an entire city.
A New Kind of Risk
The study, published in Nature Astronomy and led by Auriane Egal of the Montreal Planetarium, concluded that 2023 CX1 represents part of a previously underappreciated population of asteroids. These are space rocks linked to L-type chondrites, capable of resisting breakup until they are deep in the atmosphere, only to disintegrate all at once.
This discovery means planetary defense strategies need to adapt. Traditionally, the focus has been on larger asteroids, the kind capable of causing regional or even global devastation. But as 2023 CX1 showed, small asteroids cannot be dismissed as harmless. Their sudden fragmentation makes them unpredictable and potentially dangerous to populated regions.
Why This Matters for Humanity
Events like 2023 CX1 are reminders that Earth is not isolated but part of a dynamic solar system filled with wandering rocks. Most are harmless, burning up unnoticed as shooting stars. But every so often, one reminds us of the fragility of our world.
Unlike ancient times, when meteorites were seen as omens from the gods, today we have the tools to track and understand them. Early detection systems, international collaboration, and citizen science networks are giving humanity a fighting chance to prepare for these cosmic encounters. Yet the work is far from done.
The lesson from Normandy is clear: planetary defense is not only about giant asteroids. It is also about the small, fast, and unpredictable ones.
A Window into the Future
The recovery and study of 2023 CX1 was more than just a scientific success—it was a glimpse of the future of astronomy and planetary defense. With advances in telescopes and detection systems, we are catching more of these small objects before they arrive. Each one provides data that sharpens our understanding of the risks and helps refine strategies to keep Earth safe.
More importantly, these events remind us of our connection to the cosmos. Every meteorite is a messenger from deep time, a fragment of the solar system’s birth billions of years ago. When they fall to Earth, they not only spark scientific discovery but also awaken a sense of wonder.
Conclusion: Lessons from a Cosmic Visitor
The story of 2023 CX1 is the story of science in action: detection, observation, recovery, and analysis—all within days of a celestial event. It showed us that small asteroids can pack a surprising punch, that the atmosphere sorts fragments in strange ways, and that teamwork across nations and disciplines is essential to uncover their secrets.
It also reminded us that our planet, while beautiful and resilient, is vulnerable to the universe’s unpredictable whims. By studying these space rocks, we are not just defending ourselves—we are also learning about our origins, our place in the cosmos, and the delicate balance that sustains life on Earth.
On that February night, the sky over Normandy exploded. But what remained was more than meteorites. It was knowledge, cooperation, and a renewed determination to keep watching the skies—for in those flashes of fire, humanity glimpses both its fragility and its strength.
More information: Auriane Egal et al, Catastrophic disruption of asteroid 2023 CX1 and implications for planetary defence, Nature Astronomy (2025). DOI: 10.1038/s41550-025-02659-8.
