Depending on its size and where it hit, it could ruin your next several decades. Even a relatively small impactor -- such as the Chelyabinsk meteorite of 2013, that exploded over the southern Urals in Russia in 2013 -- did some significant damage, (fortunately) mostly to buildings. It is estimated to have been about nine thousand tonnes and eighteen meters in diameter, and when it hit the atmosphere and detonated from thermal shock, it released about thirty times the energy of the nuclear bomb that destroyed Hiroshima.
And in the grand scheme of things, Chelyabinsk was nothing more than a pebble, of which there are likely to be millions out there in the Solar System, mostly (again, fortunately) not in orbits that threaten the Earth. Bigger objects, such as the ten-kilometer Chicxulub meteorite that wrote finis to the Mesozoic Era, are fortunately far less common.
It's also a good thing that impacts have gotten less frequent over time. The debris left over from the formation of the Solar System has gradually gotten swept up by the planets, either impacting them or being gravitationally flung out into space. So comparatively speaking, we're safer now than we ever have been. Four billion years ago, during the period called the Late Heavy Bombardment, there were so many impacts from asteroids and comets that the entire surface of the Earth re-liquified. (One of the reasons that we have so few intact rocks left from the oldest periods of the planet's history.)
But just because in more recent geological history -- since, say, the beginning of the Cenozoic Era, 66 million years ago -- there have been fewer impacts, doesn't mean there have been none. The reason the whole topic comes up is a study that came out this week in Nature Communications about the discovery of a three-kilometer wide crater, surrounded by concentric faults, caused by an meteorite impact 43 million years ago, that we hadn't even known about -- because it's underneath the North Sea.
Named the Silverpit Crater, it is thought to have been due to the collision of a 160-meter-diameter meteorite, traveling something like fifty kilometers per second. The shock wave from the impact raised a tsunami estimated at a hundred meters high, that would have completely obliterated the coastlines of what is now England, Scandinavia, and the rest of northwestern Europe.
[Image credit: Uisdean Nicholson et al., Nature Communications, 20 September 2025]
While Silverpit didn't cause the global devastation that Chicxulub had, 23 million years earlier, it definitely would have caused problems, and not just for the region. The impact would have blown tons of debris up into the atmosphere, dramatically lowering temperatures across the globe -- just as the eruption of Tambora did in 1815, causing the famous "Year Without a Summer."
If such an impact occurred today, it would have horrible consequences for the entire planet, likely including mass starvation because of widespread crop failure.
The question is what we could do to prevent such a catastrophe. Even if we could detect an incoming meteor soon enough -- something iffier than ever, given Trump and his cronies' determination to completely sandbag NASA -- it's questionable that we'd have the lead time to try to deflect it into a safer path. The DART Mission did exactly that, giving a nudge to the asteroid Dimorphos to change its orbit, so that was at least proof of concept -- but the DART lander itself took years to plan and build, and for something as small as the Silverpit impactor, it's unclear we'd know about it soon enough.
Other options -- like nuking the threatening meteor in space -- are dubious. Even if you could blow up an asteroid, chances are all you'd accomplish is turn one incoming object into a hundred that were still on essentially the same trajectory.
So at present, I guess all we can do is hope for the best, and rely on the at least marginally-encouraging statistics that large meteor impacts are relatively uncommon.
Anyhow, that's our cheerful science news of the day. The universe playing a game of celestial Whack-a-Mole with the Earth. Me, I'm not going to worry about it. On my list of Stuff I'm Experiencing Existential Dread About, this one ranks pretty low. Certainly way behind climate change, various ongoing genocides, and the fact that my country's so-called leadership seems dead-set on turning the United States into Temu Nazi Germany. Given all that, a meteorite collision might almost be an improvement.
****************************************
No comments:
Post a Comment