A Western University researcher recently led the study of an effort by professionals and citizen scientists to track an asteroid through space to its safe arrival on Earth – the first such “comprehensive study”, officials said.
The asteroid, called 2023 CX1, never posed a threat to our planet. But tracking it could help with future planetary defence efforts, Western officials said in a statement. The research was led by Western adjunct professor Auriane Egal and published the Nature Astronomy journal on Wednesday (Sept. 17) .
“This unique alliance between professional and citizen scientists demonstrates the power of international cooperation when facing rare and critical celestial events,” stated Egal, an astrophysicist and scientific advisor at the Planétarium de Montréal, in a statement by Western.
The asteroid was less than a metre in diameter and had an estimated mass of 650 kg when researchers discovered it, only seven hours before impact on Feb. 12, 2023 at 10:59 p.m. EST (Feb. 13 at 2:59 a.m. GMT). The space rock broke up over Normandy, France in a way that surprised researchers.
Roughly 28 kilometers above the region – more than twice as high as a commercial airliner that cruises at roughly 12 km – the meteroid “shattered”, Western officials wrote, and “released 98 per cent of its energy in a fraction of a second – an exceptional behaviour for an object of this size.”
Fragmentation somewhat like this is familiar to the space community in the wake of the burst of a much larger meteoroid (~ 20 metres) above Chelyabinsk, Russia in 2013, which reportedly caused minor damage and injuries.
However, “computer simulations constructed after 2023 CX1’s recovery revealed [its] type of fragmentation could cause greater ground damage than typical fragmentations, like those observed for the 2013 Chelyabinsk Russia meteor event,” Western officials stated.
Scientists were able to determine this after receiving more than 100 pieces of what used to be 2023 CX1, which fell in and around Normandy. The resulting meteorite is called Saint-Pierre-Le-Viger (SPLV) and is the only L-type chondrite (a type of stony meteorite) that was observed both in space and in a laboratory. (Chelyabinsk was an LL5 chondrite, and went undetected before arriving.)
“This study highlights the need to integrate observation and analysis of pre-impact asteroids into planetary defence protocols,” Western officials said of the work on 2023 CX1. They suggested that planetary defence plans regarding L-type chondrites “may require reinforced alert systems and adapted evacuation plans in the event of a threat” over populated regions.
Watching the journey to Earth took a collaboration of both professionals in astronomy, as well as citizen scientists . Both NASA and the European Space Agency (ESA) released predictions of when and where 2023 CX1 would arrive in Earth’s atmosphere, missing the mark by a mere 20 metres. Citizen scientists also joined in to record “the first large-scale targeted observation of a meteor”, which assisted in helping scientists find the pieces on the ground after the meteoroid exploded.
Tracking, observations and data collection was performed by both space agencies, a French camera network called FRIPON/Vigie-Ciel, the Western-led Global Meteor Network, roughly 100 scientists, and citizen scientists in America, Africa, Australia and Europe.
Several other Western scientists were participants in the study. Denis Vida is founder of the Global Meteor Network, the meteoroid’s acoustic signals were analyzed by individuals including Peter Brown (a physics and astronomy professor) and Luke McFadden (a former graduate student), and the time in flight before impact included analysis by physics and astronomy professor Paul Wiegert. The original location of 2023 CX1 was calculated from a parent body in the asteroid belt, between Mars and Jupiter. Separation likely occurred about 30 million years ago, analyses showed. The asteroid is only the seventh ever found in space before impacting Earth.