Catastrophic meteors: How space scientists hope to protect 'the only planet we know'
NASA is warning that meteors pose a major threat to Earth, so agencies are already testing out ways to defend against them by using lasers or by ramming spacecraft into them.
During a conference last week, NASA administrator Jim Bridenstine explained that not taking meteors seriously could have catastrophic consequences. In 2013, a 20-metre meteor exploded over Russia and the sonic boom caused windows and glass to shatter, injuring more than 1,000 people.
That relatively small meteor contained more than 30 times the energy of the atomic bomb the United States dropped on Hiroshima during the Second World War.
"We have to make sure that people understand that this is not about Hollywood, it's not about movies," he said during the keynote speech. "This is about ultimately protecting the only planet we know, right now, to host life, and that is the planet Earth."
Unfortunately, that wasn’t a one-off event.
For example, the Tunguska event flattened around 2,000 square kilometres of Siberian forest in 1908 and another was reported in Brazil in 1930. Similar devastating meteor strikes are expected to happen once every 60 years, according to scientific modelling systems.
And some – those more than 43 metres in diameter -- could be large enough to destroy cities. One larger than that could even decimate entire countries.
Canada hasn’t been exempt. In 2008, a 41-kilogram meteor was seen breaking apart over Alberta, Saskatchewan and Manitoba. And the Manicouagan crater in Quebec was left after an five-kilometre wide meteor collided with Earth over 200 million years ago.
Jeremy Wang, CEO of the commercial drone company The Sky Guys, said despite Canada’s size, the country’s population density is sparse enough that the likelihood of personally being affected would be quite low.
“However, Canada as a country doesn’t have its own planetary defence system,” he told CTV Your Morning. “That’s really more of an international effort that’s collaborated on by NASA, [Canadian Space Agency], the European Space Agency and others.”
Potential defences range from high-concept ones to others which are fairly possible in the next five to 10 years, Wang said. “Broadly speaking, planetary defence measures come in two flavours: you either destroy the object or you delay or deflect the object.”
But he explained destroying the object is unfavourable because this could “create multiple objects Earth would need to worry about.” Therefore, deflecting the meteors is the better option.
These options can include using a laser to nudge their trajectories or by using so-called “gravity tractors” whose gravitational pull will drag the meteor or asteroid off course.
“But the most feasible one in existence today is the kinetic impactor -- so we’re talking about bringing a spacecraft to an incoming object and literally smashing into the side … at more than 10,000 mph,” Wang said.
In fact, earlier this month, SpaceX was awarded a $69-million government contract to provide launch services for NASA’s Double Asteroid Redirection Test mission, which will test out the ability to deflect an asteroid by colliding a spacecraft into it at high speed.
Additionally, NASA is currently moving towards a goal of detecting and tracking 90 per cent of near-Earth asteroids larger than 140 metres or more.
Models indicate there are around 25,000 of these sized objects whose orbits come in close proximity to Earth, but so far Bridenstine said NASA has only detected 8,000 of them -- or less than one third.
“This is a priority of the United States and we want it to be a priority of the world,” he said. “We want more international partners that can join us in this effort.”