The Risk of an Asteroid Strike

You gotta hand it to the human race. We picked a great neighborhood.

Weather’s just right.

No nosy neighbors.

Plenty of room to go outside and stretch your legs.

And, hey, it’s about as safe as neighborhoods come.

Well … most of the time.

[OPENING SEQUENCE]

We don’t mean to alarm you, but the world may end on October 26, 2028…

… is what you may have heard if you were listening to the news in March of 1998.ⁱ

That’s when astronomers found a half-mile wide asteroid that looked like it was headed for Earth. Now, that’s only a fraction of the size of the asteroid that took out the dinosaurs … but that probably wasn’t much comfort when the New York Times reported that it would “not necessarily be severe enough to wipe out the human race.”ⁱⁱ

We were lucky. Further calculations revealed that the asteroid in question wasn’t destined for Earth after all. But the topic still weighed heavily on people’s minds that year.

How could it not? Hollywood released not one, but two asteroid movies in 1998. In Deep Impact, an asteroid took out most of the East Coast. In Armageddon, the future of humanity hinged on Bruce Willis and Ben Affleck — which, honestly, may have been the more terrifying scenario.

1998 was also the year that NASA created a program to systematically track what are called NEOs — Near-Earth Objects — that come within 30 million miles of Earth’s orbit around the sun.ⁱⁱⁱ That may not sound close, but in the context of space … let’s just say you’d want those asteroids to use their turn signals.

The fact that NASA took it so seriously underscores an important point: This threat is not just a creation of Hollywood. Most of us know about the massive asteroid that hit Mexico about 66 million years ago and took out the dinosaurs — although we might not know the terrifying details. One author described it as “a rock larger than Mount Everest hit[ting] Planet Earth traveling twenty times faster than a bullet.”^iv

Fewer of us, however, know about other, more recent occasions, on which Earth has taken a beating.

In 1908, an asteroid exploded over the Tunguska region of Siberia with the same force as the volcanic eruption at Mt. St. Helens.^v Thankfully it took place over a remote area, so its main impact was flattening half a million acres of trees — on a different path, it could have destroyed a major city.

In 2013, another asteroid blew apart 14 miles over the Russian city of Chelyabinsk — with the force of 440,000 tons of TNT.^vi It blew out windows over 200 square miles.

And it’s not just Russia. On New Year’s Day 2022, an unexplained shock wave that hit Pittsburgh was believed to be part of an asteroid that either exploded or vaporized over the city.^vii

On one hand, we’ve been very lucky. Humanity has never yet faced a doomsday asteroid — a challenge that, for the vast majority of human history, we would’ve been totally powerless against. In fact, up until recently, we couldn’t even track them well. The first time that scientists correctly predicted when and where an asteroid would strike Earth … wasn’t until 2008.^viii

Don’t worry. It was harmless.

On the other hand … we know that luck won’t last forever. The most recent research estimates that massive impacts of the kind that killed the dinosaurs happen about every 250 million years, on average.ix But smaller strikes are far more common. NASA says they could happen “at any time.”^x

And the potential consequences could be disastrous. Last year, a report from the White House Science & Technology Council modeled what an asteroid of the type that exploded over Tunguska could do if its ultimate destination was New York City. This was the result.^xi

So, we’ve got two problems: how to find these asteroids and how to stop them. And the news on both fronts is … mixed.

When it comes to detection, the good news is that NASA has found over 90 percent of the massive objects that could pose potentially catastrophic danger to the planet if they were ever headed for us. The … less-than-good news is that, of the smaller objects that could devastate cities or even entire regions, they’ve only found about 40 percent so far.^xii

Now, this isn’t because NASA’s asleep at the switch. This is incredibly hard work. The asteroid that exploded over Chelyabinsk , for instance, couldn’t be found because it was coming from the direction of the sun. Any telescope pointed towards it would literally have melted.^xiii

While our technology is getting better, there’s one step in particular scientists think is necessary to keep us safe: an infrared telescope launched into space for the sole purpose of asteroid detection.^xiv That would allow us to see a vast array of objects that currently avoid detection.

Which … yeah, feels worth doing.

Of course, that leads to the question of what we do when we … [gulp] find a problem. In late 2021, NASA took an initial step with the launch of DART, an experiment that will “see if intentionally crashing a spacecraft into an asteroid is an effective way to change its course.” ^xv

That’s NASA’s actual description of it.

That’s how awesome their jobs are.

Oh, also, the asteroid in question is not a threat. But, whatever, still kick-a**.

Of course, there’s always the chance that we have too little time — or an asteroid is simply too big — to take any but the most extreme measures.

And, yes, we’re here to report that NASA is actually exploring the feasibility of planting a nuclear weapon inside a killer asteroid.^xvi The technology isn’t there yet and it’s still nothing more than a proposal. But it’s an actual scenario some of the world’s best scientists are considering.

The bottom line: The better we get at seeing what’s coming at us, the more likely that we’ll never have to face choices that hard.

Otherwise, the odds only increase that someday humanity will face a crisis almost too dire to contemplate…

… having to rely on Bruce Willis and Ben Affleck.