An asteroid has fragmented in an unexpected way<\/p>\n
Wikimedia\/CC-BY-SA-4.0<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
An asteroid exploded over France two years ago in a rare single explosive event, raising concerns about future planetary defence from certain types of these rocky bodies.<\/p>\n
On 13 February 2023, a small asteroid called 2023 CX1 entered Earth\u2019s atmosphere and streaked across the skies of Normandy. The event was one of only a handful of meteors that have been tracked before they enter our atmosphere, this one being seen about seven hours before.<\/p>\n
The event produced a bright fireball and multiple meteorites that were collected on the ground. Only two asteroids have been tracked and had fragments recovered from a fall on the ground; the second was in Germany in 2024.<\/p>\n
<\/p>\n Examining footage from cameras that tracked the asteroid\u2019s descent, Auriane Egal at the University of Western Ontario in Canada and her colleagues spotted something unusual. Most asteroids gradually break apart as they enter Earth\u2019s atmosphere, but 2023 CX1 seems to have survived almost entirely intact until it reached an altitude of 28 kilometres, where it exploded in a single catastrophic event with an energy of about 0.029 kilotons, equivalent to about 29 tons of TNT, and lost about 98 per cent of its 650-kilogram mass in a fraction of a second.<\/p>\n \u201cIt was similar to a bomb,\u201d says Egal, adding it was a \u201csingle blow that generated one spherical shockwave, not multiple detonations all along its trajectory\u201d.<\/p>\n Asteroid 2023 CX1 was small, only about 72 centimetres across \u2013 about the size of a beach ball \u2013 so it didn\u2019t cause any problems on the ground. But if a larger asteroid exploded in a similar manner, it could cause more damage than one that disintegrated more gradually in the atmosphere.<\/p>\n Only one asteroid has been seen exploding in such a way before: the Novo Mesto meteor over Slovenia in 2020, which lost about 80 per cent of its mass in a single explosion.<\/p>\n \u201cThis kind of fragmentation is more dangerous,\u201d says Egal. \u201cIf you have a larger asteroid, its effects are going to be amplified. Maybe we need to evacuate a larger area near the predicted impact location,\u201d if the asteroid were large enough that such action were necessary.<\/p>\n A new meteorite from asteroid 2023 CX1, found in February 2023 near Dieppe, in Normandy, north-western France<\/p>\n LOU BENOIST\/AFP via Getty Images<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n Why this asteroid survived much lower in the atmosphere isn\u2019t entirely clear, but it might be related to its origin. The asteroid was a fairly common type known as an L chondrite, comprising about a third of all Earth\u2019s meteorites, and possibly originated from a parent asteroid in the inner asteroid belt called Massalia that had experienced collisions before, toughening 2023 CX1 before it encountered Earth, according to Egal and her team, who studied a meteorite from the fall.<\/p>\n \u201cWe have multiple shock veins in the meteorite that are witnesses [to] lots of impacts,\u201d she says. \u201cMaybe this network of veins glued the rock together, and that\u2019s why it holds better than other typical meteorites.\u201d<\/p>\n That might mean we need to be wary of similar L chondrite asteroids in future, particularly larger ones, says Thomas Burbine at Mount Holyoke College in Massachusetts. \u201cIt\u2019s a very common meteorite type, so this is the biggest worry,\u201d he says. \u201cThese L chondrites could cause more damage than expected.\u201d<\/p>\n Experience the astronomical highlights of Chile. Visit some of the world\u2019s most technologically advanced observatories and stargaze beneath some of the clearest skies on earth.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<\/section>\n Topics:<\/p>\n<\/section><\/div>\n![\"A](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2025\/09\/17094951\/SEI_266474201.jpg\")
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\n <\/picture>\nThe world capital of astronomy: Chile<\/h3>\n