The Daily: 30 June 2024

Today is International Asteroid Day. This day was created by the United Nations in 2016 to commemorate the Tunguska Event in East Siberia near the Podkamennaya Tunguska River on 30 June 1908. An asteroid of about 50 meters in diameter smashed into Earth’s atmosphere on this day, killing several people and flattening some 80 million trees over an area of 2150 square kilometers (830 square miles). There was no crater; the asteroid detonated some 5-10 kilometers (3-6 miles) above the ground.

The UN envisioned this commemorative day as an opportunity to raise awareness of the hazards of impact with extra-planetary bodies. After all, an asteroid of about 10 kilometers in diameter ended the Mesozoic Era and cut dinosaurs down to song-birds and chickens. (And roadrunners… which are frankly terrifying…)

It is possible that an asteroid impact also played a role in the Permian Extinction, though the enormous outpouring of basalt known as the Siberian Traps would have been devastating enough, causing the extreme cold we see for some two million years spanning the end of the Permian and the beginning of the Triassic. Outsized volcanic activity or asteroid impact — both could cause an abrupt ice age and drastic lowering of sea levels. They could also be related. A massive impact has tectonic effects, potentially fracturing the Earth’s crust, depressurizing the mantle, and causing volcanism on an enormous scale.

(Note that a large thermonuclear detonation could have similar effects…)

To further substantiate the potential link between impact and flood volcanism, the largest magmatic emplacement left on continental crust, India’s Deccan Traps, happened about the same time as the dinosaur-killing asteroid impact. The timeline is not exact, so there are still questions, but… big things slamming into a tectonically active planet are bound to cause ruptures. And there are thousands of near-Earth objects that have impact potential.

So there are hazards. Just… well, rather unlikely hazards. Though it makes for fun fiction.

As with many spacey narratives, the excitement behind near-Earth object impact is more of a tech than a science nature. Things that could crash into the planet seems like a good excuse to make really big guns and so on to intercept potential collisions. And corporations that specialize in guns and rockets start slavering at the thought of the enormous budgets states will throw at guns and rockets — for defense, of course, so it’s all guilt-free. We can make and fire off the biggest guns and rockets imaginable and no cute fuzzies will be harmed. Just menacing balls of space rock.

At least, that’s what I imagine is behind the excitement. Because once every two hundred million years or so is really not a going concern. Though I also imagine that the guns and rockets would find other uses… And that is a concern.

I am usually far more worried about destructive tech than I am about destructive nature. After a few decades of nothing to do with the big guns and rockets — given that we have a couple decades of this suicidal economy, which may not be true — it seems rather too likely that humans will want to use this tech in other ways, if for no other reason than to drum up a market for these expensive, and potentially lucrative, toys.

One reason space tech is so seductive is that it doesn’t have to succeed. There are no consequences, no negative publicity. We can churn out piles of guns and rockets and never have to prove that they work as designed… Unlike all the tech schemes and investments notably failing to have any impact on the messes we’ve made on this planet with no extraterrestrial assistance whatsoever. Messes that are destabilizing the biosphere much more effectively and efficiently than anything caused by a mere space rock. Messes that have come about largely because of our tech-marketing obsessions.

You’ll excuse me if I don’t quite believe that guns and rockets are going to save us.

So instead of drawing attention to the hazards, I’d like to spend today thinking about all the weird stuff that is floating around in near space. Where I did my doctoral work, we had a whole team of folks studying the bric-a-brac that has hit our planet in completely un-newsworthy fashion. There’s even a museum! If you live near Albuquerque, go check it out. Nothing asteroid-scale, but there are pieces of asteroids, as well as stranger exotica, like chips of ancient planetary cores and Oort Cloud space junk from several star systems before our Sun. It’s astounding!

And if you need something to hyperventilate over… it’s raining in Vermont again… and Canada’s on fire. And there is no tech valiantly coming to save us from ourselves.

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©Elizabeth Anker 2024