3 Times Space Almost Killed Us | Unveiled

3 Times Space Almost Killed Us

Look up into the sky at night and try not to be amazed. It’s impossible. With the entire cosmos stretching out before you, one glance at the stars on a clear night is enough to make anyone feel humbled. But, also, in amongst the awe and wonder, you might experience just a little bit of unease. A small helping of fear. And with good reason.

This is Unveiled, and today we’re uncovering three astronomically terrifying times when space almost killed us.

There’s no doubting that space is dangerous. The vast majority of it is a near-vacuum of near-certain death, were a human being ever to be exposed to it. But, to get into space you have to travel at least fifty miles into the sky, according to NASA. Or sixty-two miles, according to the World Air Sports Federation. The debate over exactly where the edge of space is still hasn’t been definitely resolved… but what’s clear is that we don’t need to leave the ground at all for it to cause us problems. Major problems. In this video, we’re taking a closer look at three times in recent history when space most threatened human civilization.

First, we’re talking meteors and meteor showers. The Perseids have routinely flashed across the Earth’s sky for thousands of years, now. They’re a shower of space debris, brought along and deposited in the solar system by the periodic comet 109P/Swift-Tuttle. And most of the time… they’re of no concern. Streaking across our horizon in July and August every year for an often spectacular, cosmic light show. But the Swift-Tuttle comet that brings them has also been referred to before as the “most dangerous object known to humanity”, by the science writer Gerrit Verschuur in his 1996 book, “Impact”. So, why’s that?

The Swift-Tuttle comet has a 133-year orbital period. This means that while Earth passes by its meteor shower every year, it’s only once every 133 years that the comet itself makes a close approach with our planet. The last time this happened, the last time Swift-Tuttle sped through the inner solar system, was in 1992.

Naturally, because we’re all still here today to watch YouTube videos all about it, Swift-Tuttle didn’t pass close enough to impact us back then. If it had done, then scientists predict that it would have triggered an extinction event the like of which Earth hasn’t seen for millions of years. But it is still deemed to be one of the biggest known astrological objects passing the closest to the Earth-Moon system. And what perhaps is a little concerning is that, so far, our attempts to track it haven’t been totally reliable.

When Swift-Tuttle passed through our region of the solar system in the early 1990s, it did so at a rate (and on a path) that defied previous predictions by seventeen days. As it happens, there was no harm done, and no surprise impact event as a result… but it was also calculated that if our predictions fail by a similar degree when Swift-Tuttle next makes a close approach, in the year 2126… then the chances of it hitting Earth increase. Some astronomers also fear that the gravity of Jupiter could one day divert this particular comet straight towards us. Thankfully, for today’s generation, this isn’t what happened in 1992… and disaster was somewhat narrowly avoided.

It was a similar story of catastrophe-that-could-have-been twenty years later, in 2012, as well. Only this time the culprit wasn’t a comet, it was a solar storm. In July 2012, a super-powerful Coronal Mass Ejection (or CME) seared through Earth’s orbit, coming extremely close to the planet itself. A CME is when the sun fires plasma and magnetic energy out across the rest of the solar system. In themselves, CMEs aren’t all that rare. But one as strong as in 2012, reaching as near to Earth as it did… we just don’t see that very often!

The near miss quickly drew comparison with the Carrington Event, a CME that did hit Earth back in 1859, triggering a massive geomagnetic storm on the ground. But what does that mean? In 1859, the effects were more limited. The storm caused major issues and outages across telegraph systems, but most reports more prominently feature the seeing of bright lights and auroras in the sky. The focus was on the beauty of a CME as a cosmic spectacle.

Had the same thing happened in 2012, though, we would have seen considerably more problems. So much of the modern world relies on our electrical systems and communications networks… but these would’ve all been fried had the 2012 CME erupted from the sun just a few days earlier, or just a few degrees in a different direction. It would’ve meant blackouts across the planet and, according to NASA, it could’ve disabled “everything that plugs into a wall socket”.

Now, in some cases, this wouldn’t have amounted to space almost killing us. It would’ve just meant your TV switching off, or your kettle refusing to boil. But think about the countless, life-saving products and procedures that also rely on a steady power source every single day… in hospitals, on roads, on airplanes and in tech companies. These might’ve all been at risk, too. There’s little doubt that if a large enough CME were to rip through today’s infrastructure, then people would die. After the 2012 event, a study by Lloyds also estimated the financial impact - predicting that the rebuild for just the United States may have cost more than two trillion dollars. And various estimates have claimed that the world in general would’ve still been recovering today.

Finally, let’s look into asteroids. Many a Hollywood disaster movie has focussed on this particular doomsday scenario. But not without reason. We’re constantly scanning the skies from all corners of the planet, keeping our eyes peeled for the next big rock that might just end it all. The scary thing is, though, that often we miss them!

One such asteroid passed by Earth in July 2019. It was dubbed 2019 OK… but things really wouldn’t have been OK, if it had struck us. With an estimated diameter of around 400 feet, it came within 40,000 miles of our planet - a distance roughly equivalent to one-fifth of between here and the moon. Nevertheless, it was only spotted hours before it passed at its closest approach. Up until that point, we hadn’t been expecting anything to happen!

At the time, NASA described 2019 OK as a “pretty unusual event” and something that happens “about twice a century”. The unusualness mostly relates to how close it came, and the risk level rising as a result of that… because if it had hit, then estimates say the explosion could’ve destroyed an area of at least fifty square miles. For anyone in or around that area, 2019 OK would most certainly have been life threatening. And you would only have had a matter of hours to learn of and escape it!

The fact is that there are so many asteroids careening through our solar system, that even the world’s topmost astronomers and most specialist telescopes have a hard time keeping up with them all. One rock that we are reasonably sure on, though, is 4581 Asclepius.

Asclepius was discovered in 1989, and in March of that year it passed within 425,000 miles of Earth. That’s ten times further away than 2019 OK, but Asclepius is also more than double the size… and it’s part of the largest group of near-Earth objects we have, the Apollo asteroids, of which there are more than ten thousand in total! The Chelyabinsk event was also thanks to one such Apollo asteroid, exploding over Russia in 2013. Scientists keep such a keen eye on Asclepius, though, because its orbital path takes it past Earth again and again in the future - with notably close approaches predicted in the years 2051 and 2105.

So, what can we learn from these past events (and ongoing cosmic phenomena) to help us prepare to defend against space in the future? Ultimately, we’re still trying to make sense of it all! We do know more today than ever before about meteor showers, solar storms and near-Earth asteroids… but that doesn’t mean that any one of those things couldn’t suddenly hit Earth and cause unparalleled chaos.

Against the vast expanse of the solar system and the universe we, striving to eke out our lives on this humble rock, are still almost completely helpless. We’re at the mercy of nature… so let’s hope it doesn’t turn against us in a big way anytime soon! Because those are three astronomically terrifying times when space almost killed us.