Asteroid 2023 CX1
The article about investigations of asteroid 2023 CX1, published on 17 September in the prestigious scientific journal Nature Astronomy, generated great interest even outside the scientific community.
The article about investigations of asteroid 2023 CX1 (Catastrophic disintegration of asteroid 2023 CX1 and implications for planetary protection), published on 17 September in the prestigious scientific journal Nature Astronomy, generated great interest even outside the scientific community. This article confirmed the existence of a population of asteroids that can release almost all their energy at once in the Earth's atmosphere near the surface, thereby increasing the risk of potential damage in the area of their impact.
Asteroid 2023 CX1, whose fall was observed on February 13, 2023, in Normandy, is the seventh asteroid that was registered even before its entry into the Earth's atmosphere. It is the first cosmic object that was comprehensively monitored (for approximately 7 hours) from its discovery to its entry into the atmosphere, explosion and dispersion into many fragments, of which almost hundred have been recovered. The asteroid comes from the inner asteroid belt in the region between Mars and Jupiter. It is the result of a collision with another asteroid 30±3 million years ago, after which it traveled as a separate object in the inner solar system. The asteroid was approximately spherical in shape with a diameter of 72±6 cm and a mass of 650±160 kg.
Small asteroids usually start to disintegrate high in the atmosphere, gradually releasing their energy. However, the studied asteroid remained intact up to an altitude of 28 km, and then exploded within one second, releasing 98% of its total energy. The explosion created a powerful spherical shockwave that spread over a much larger area and was closer to the Earth's surface than usual. Therefore, observations in the atmosphere have revealed its potentially high-risk fragmentation behavior, which requires a critical reassessment of the Earth’s asteroid protection strategy, including planning for the evacuation of the population from the endangered area.
The area determined by the calculations contained most of the fragments, which are known as the Saint-Pierre-le-Viger meteorite, after the village in Normandy where the first fragment was found. The meteorite belongs to ordinary L chondrites, which are relatively common, but it was the first time a meteorite of this type came from an object that was identified before its impact on Earth.
An international consortium of experts from various scientific fields was quickly formed to be responsible for its investigations. Nuclear physicists from the Department of Nuclear Physics and Biophysics FMFI UK (Ivan Kontuľ, Ivan Sýkora and Pavel Povinec) were also members of the consortium, as well as co-authors of the article in Nature Astronomy. They analyzed four meteorite fragments in low-background gamma-spectrometers. Two of them were analyzed two weeks after their impact, which made it possible to determine both the long-lived (Na-22, Co-60 and Al-26) and short-lived (Sc-46, V-48, Mn-54, Co-57, and Co-58) cosmogenic radionuclides. These radionuclides are formed in the asteroid as a result of collisions with cosmic ray particles during its journey through the solar system (the so-called exposure age). Our main contribution was the determination of the pre-atmospheric size of the asteroid, as well as its exposure age.
The article attracted a lot of attention, as confirmed by dozens of agency reports within a week of the article's publication and its inclusion in the top 5% of all scientific outputs by Altmetric (https://nature.altmetric.com/details/181458008/news).
Source: A. Egal et al.: Catastrophic disruption of asteroid 2023 CX1 and implications for planetary defence. Nature Astronomy (2025). DOI: 10.1038/s41550-025-02659-8.