In his keynote address at the 2019 IAA Planetary Defense Conference in College Park, Maryland, USA, on Monday (April 29), NASA administrator Jim Bridenstine warned that the threat to Earth from asteroid strikes was as real as it gets.
He urged the international space community to create awareness among people that devastation from asteroid strikes was not only about what Hollywood shows us but about defending Earth – the only habitat we know of.
“We have to make sure that people understand that this is not about Hollywood, it’s not about movies,” Bridenstine was quoted by Space.com as having said at the conference.
“This is about ultimately protecting the only planet we know right now to host life, and that is the planet Earth,” said the NASA head.
As part of the “National Near-Earth Object Preparedness Strategy and Action Plan” announced in June last year, this gathering of NASA, FEMA, ESA (European Space Agency) and the International Asteroid Warning Network representatives, among others, will conclude on May 3.
The five-day event will see the participants conduct an “asteroid impact exercise,” playing out mock impact scenarios to enhance preparedness for the real thing if, or should we say when, it does happen.
Asteroid expert Andrew Rivkin – a planetary astronomer at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, told NBC News MACH in an email that “exercises like this have been run at several conferences over the years, and government agencies have also had them.”
“It’s definitely worth doing, if only so people are aware of the issues and how complex some of them are,” he wrote.
Comparing the exercise to a fire drill, Rivkin said that the aftermath of a major asteroid hit would be catastrophic if what happened to the dinosaurs is anything to go by.
He was, obviously, referring to the six-mile-wide asteroid that hit our planet some 65 million years ago, wiping out the dinosaurs from the face of the Earth – or, so it is believed.
But. we need not end up like the dinosaurs, or the other species that went with them, because we have the necessary resources at our disposal; we just have to make the most of them.
“We know for a fact that the dinosaurs did not have a space program. But we do, and we need to use it,” Bridenstine said.
But, why go so far back in time to emphasize the threat we’re exposed to, when the recent Chelyabinsk Event is scary enough to justify all the good things, including the ongoing conference, being done to minimize the probabilities of a repeat.
The 66-foot-wide supersonic meteor smashed into the atmosphere above the city of Chelyabinsk in the Ural Mountains, sending shockwaves so powerful that at least 1,500 people were injured and more than 7,000 buildings in six cities were damaged.
“I wish I could tell you that these events are exceptionally unique, but they are not,” Bridenstine said about the Chelyabinsk Event.
“These events are not rare — they happen. It’s up to us to make sure that we are characterizing, detecting, tracking all of the near-Earth objects that could be a threat to the world,” he added.
The aforementioned Federal ‘preparedness strategy and action plan’ notwithstanding, there’s a lot that still needs to be done in terms of increased monitoring systems across the globe, for which international cooperation is the need of the hour, says Bridenstine.
“We’re only about a third of the way there,” he said, adding: “We want more international partners that can join us in this effort.
“We want more systems on the face of the Earth that can detect and track these objects, and we want to be able to feed all of that data into one single operating system so that ultimately, we have the best, most accurate data that we can possibly get.”
NASA knows that merely chasing these potential threats is not going to save Earth from another mass extinction and, probably, thousands of years of ice-age, should one of them slam into us.
The good news is that the agency has been working on a planetary-defense mission called DART, an acronym for Double Asteroid Redirection Test, to save us from exactly such an eventuality.
DART is essentially an impactor spacecraft that NASA plans to crash into an asteroid satellite at 13,500 miles per hour in an effort to change its course.
The idea is to find out how much the car-sized impactor can change the trajectory of the target space rock and whether it’s enough to redirect an Earth-bound asteroid safely away from us.
The space rock that NASA has in its crosshairs for the planned Oct 2022 hit is, in fact, a satellite moonlet nicknamed Didymoon, about seven million miles away from Earth.
Measuring 150 meters across, the moonlet orbits an 800-meter-wide asteroid called Didymos, from where it derives its nickname.
While Didymoon is not on a collision course with Earth and poses no threat to us whatsoever, a detailed study of the space object, and then slamming into it to bump it off its bearings, should provide the DART team with useful data that can come in handy in averting a real asteroid threat, if ever it came to that.
Not only will ground telescopes track the new course of the twin objects post-impact, but an Italian Space Agency CubeSat called ‘Light Italian CubeSat for Imaging of Asteroids’ will accompany the mission to keep an eye on proceedings.
Additionally, as part of an international Asteroid Impact Deflection Assessment (AIDA) mission, the European Space Agency (ESA) will launch two CubeSats, APEX (Asteroid Prospection Explorer) and Juventas, onboard the agency’s Hera spacecraft, in time to reach the binary asteroid system sometime in 2026 to record the effects of the DART collision, according to NASA.
To test potential techniques in “deflecting” an asteroid – one of the preferred methods for mitigating a threat – DART will travel to the Didymos binary asteroid system via its a xenon-based electric propulsion system, steering with an onboard camera and sophisticated autonomous navigation software,” says NASA.
DART is expected to send back a close-up shot of the Didymoon surface – its last transmission to Earth – just before it is pulverized into space dust.
For any Solar System body to qualify as a near-Earth object, its closest approach to the Sun has to be less than 1.3 astronomical units (AU), the equivalent of nearly 121 million miles.
Among the 20,000 near-Earth asteroids and comets orbiting the Sun is a 500-meter-wide asteroid called Bennu, which has a 1-in-2,700 chance of smashing into Earth sometime between 2175 and 2196, say scientists.
The potentially hazardous object (PHO), “listed on the Sentry Risk Table with the second-highest cumulative rating on the Palermo Technical Impact Hazard Scale,” is currently 54 million miles from Earth.
For all we know, Bennu might just turn out be the asteroid that NASA has to knock off-course to save the planet in the future; that’s when the knowledge gained from the DART mission will come in handy – unless the 500-meter rock, or some other NEO, hits us sooner.
Honestly, that’s unlikely, but time will tell.