This text is part of the special Research section
Space. This place, both fascinating and brutal, where emptiness, cold and silence reign, is host to strange ballets as majestic as they are dangerous: meteor showers. The astrophysicist and curator of the meteorite collection at the Montreal Planetarium, Auriane Egal, examines these phenomena with unfailing passion, in order to better understand and predict them.
Who hasn’t dreamed of seeing fleeting shooting stars while contemplating the celestial vault? This magical spectacle is observed when dust, whose size varies between a few micrometers and a few meters, passes through the atmosphere, heats up and then produces a bright light. “We call them meteoroids when they are in space, meteors when they enter the atmosphere and meteorites when they impact the ground,” explains Auriane Egal, associate professor and member of Western Meteor Physics. Group from the University of Western Ontario, a world-renowned research team.
Most meteoroid swarms come from comets, gigantic cosmic snowballs that partially melt as they approach the Sun, then eject clouds of dust that wander the universe. Auriane Egal studies these phenomena to predict their date and intensity using supercomputers. In other words, it constructs a virtual solar system, composed of a comet and millions of small particles that it causes to evolve over hundreds or thousands of years.
Its work helps limit the risks of meteoroids colliding with space vehicles, satellites and telescopes. It collaborates in particular with NASA’s Meteoroid Environment Office (MEO) to protect astronauts who live on the International Space Station from potential threats. “Encountering a fast, one-centimeter meteoroid in space is the equivalent of being hit by a bus traveling at 100 km/h on Earth,” she illustrates.
The researcher allowed the European Space Agency to redirect the course of one of its probes, threatened by a meteor storm. She also predicted another storm, originating from Halley’s Comet, when no one agreed with her. “It happened a little later than expected, so I hid under my desk while waiting,” she recalls with a laugh. But in the end, I was right, and it’s the best model I’ve developed so far. » The International Astronomical Union (IAU) even named an asteroid “Equal” to highlight its contribution. Just that.
Between astronomy and adventure
His interest in space dates back to his early childhood, spent in Spain. “My father remembers a conversation, when I was in primary school, during which I said I loved looking at the stars with him because we felt good and very small,” says Auriane Egal. A few years later, she completed her graduate studies in fundamental physics and astronomy in Paris, before completing her postdoctoral fellowship at the University of Western Ontario, to specialize in the modeling of meteor showers. Now an associate professor, she supervises two students there.
During her studies, she carried out several field missions, including searching for meteorites in the Atacama Desert, Chile. She recounts with self-deprecation another stay, in Sri Lanka, after only ten days of preparation, to film the fall of debris from an old Apollo mission remaining in orbit between the Earth and the Moon. “We needed electricity for the cameras, so a man went to cut a tension cable with a machete, between two pylons, and handed it to me,” she relates. I was electrocuted and couldn’t lift my arms for three days. » A kleptomaniac monkey also tried to steal their cameras… Which ultimately were unable to capture anything, because of the rain.
A funny expedition which clearly did not slow down the astrophysicist. At the Montreal Planetarium, she has just been appointed curator of the meteorite collection at the age of 33. Most of its time is devoted to research, popularization, conferences and educational activities. Auriane Egal is also responsible for the Quebec component of the Meteor Detection and Observation (DOMe) project, a network of cameras in Quebec to identify falling meteors. If a meteor crosses the sky, it is she who will calculate its trajectory, estimate the point of fall and contribute to research in the field. This has not yet happened in Quebec.
Asteroids under surveillance
In 2023, however, these same cameras captured an asteroid exploding over the English Channel, between France and Great Britain. Auriane Egal coordinated the consortium of 70 Quebec and French scientists who examined its fall. “We calculated the trajectory of the fragments that fell in France, which helped direct the teams to find the meteorites and analyze them,” she explains. It was the first time that we had precise data on the trajectory of a meteoroid in space, in the atmosphere and then on Earth. » Public input was essential in filming and helping to recover the pieces on site.
Not all rains present the same risks. Asteroids [de gros météoroïdes] which could cause significant damage to the planet are monitored by the telescope networks of space agencies. Apophis, an asteroid that will brush against Earth in 2029, was detected in 2004. “Smaller objects, on the other hand, are identified only a few hours before the impact,” she continues. We can’t send anything to destroy them like in the movie Armageddon. If there is danger, we evacuate the populations. » As NASA’s DART mission proved, it is still possible to deviate an object slightly from its course.
These technologies and knowledge were not as developed in 2013, when a meteor flew over the city of Chelyabinsk, Russia, causing a shockwave that injured nearly a thousand people. The power released into the atmosphere is equivalent to around thirty atomic bombs, according to the astrophysicist. Statistically, this type of event occurs approximately once or twice per century.
With boundless curiosity, the researcher unconditionally loves her job, thanks to which she never stops learning. “Looking back, I couldn’t have chosen a better specialty,” she says with contagious enthusiasm. Meteors probably helped shape the Earth as it is today, the appearance of water, of life. »
Auriane Egal values the privileged bond she maintains with the Earth as a physical object, but also with the humans who inhabit it. “I like to say that I do local astronomy. The more I study space, the more I love the Earth and feel the desire to preserve it, to cherish it. » Sensitive to climate issues, she believes that space technologies can constitute a means of better protecting our ecosystems, but are not an end in themselves.
This content was produced by the Special Publications team at Duty, relating to marketing. The writing of the Duty did not take part.