250918.2023CX1
Fotografia del bolide scattata da Gijs de Reijke, ripresa dalla riserva naturale di Kampina nei Paesi Bassi. Credits: Gijs de Reijke
By Dario Barghini
For the first time, an asteroid has been tracked from its discovery in space all the way to the recovery of its meteorites on the ground. The study, in which INAF participated, opens new perspectives for planetary defense.
An asteroid discovered just seven hours before hitting the Earth is now the focus of the first study to fully reconstruct its trajectory, atmospheric disintegration, and subsequent meteorite recovery. The asterroid in question is 2023 CX1, which exploded in the skies over Normandy on the night of February 13, 2023. The research — led by the Fireball Recovery and InterPlanetary Observation Network, the Montréal Planetarium, and the University of Western Ontario, and carried out by about a hundred scientists worldwide, including the Italian National Institute for Astrophysics (INAF) — has been published today in Nature Astronomy.
Discovered on February 12, 2023, at 20:18 UTC at the Piszkéstető station of the Konkoly Observatory (Hungary), 2023 CX1 is only the seventh asteroid ever detected prior to its impact. Immediately after its discovery, it was tracked by a vast network of professional and amateur observatories worldwide, which contributed to determining its orbit, shape, and rotation. The timing and location of the impact were estimated with an error margin of less than 20 meters — an unprecedented level of accuracy.
With a diameter just under one meter and a mass of about 650 kilograms, the asteroid entered the Earth’s atmosphere over the English Channel at a speed greater than 14 kilometers per second — more than 50,000 kilometers per hour — heating up and turning into a fireball, that is, an extremely bright meteor. During this phase, it was observed by several sky-monitoring networks (meteor and fireball networks), including FRIPON/Vigie-Ciel, which is partnered with PRISMA (the First Italian Network for Meteors and Atmosphere systematic surveillance), coordinated by INAF and the second international partner of FRIPON.
The asteroid disintegrated on February 13, 2023, at 02:59 UTC at an altitude of approximately 28 kilometers, releasing 98% of its kinetic energy in a single explosion and generating a powerful spherical shock wave. The phenomenon dispersed over a hundred meteorites, which were recovered in the following days in the predicted impact area and classified under the official name Saint-Pierre-Le-Viger (SPLV), the location where the first sample was found.
The study, published in Nature Astronomy, co-authored by Dario Barghini and Daniele Gardiol of the Astrophysical Observatory of Turin, analyzes in detail both the observations of the asteroid in orbit and the atmospheric fireball, and finally the recovered meteorites. This study represents a unique case: it is the first time that asteroid material has been studied along its entire journey, from space to the laboratory. The analyses indicate that 2023 CX1 was a fragment of an asteroid in the inner main asteroid belt, located between Mars and Jupiter, from which it broke off about 30 million years ago.
For further information:
The scientific article: “Catastrophic disruption of asteroid 2023 CX1 and implication for planetary defence”, Auriane Egal et al., published in the journal Nature Astronomy.
Media INAF press release (in italian)
