Every asteroid that will ever strike Earth is already out there and already on course to strike Earth. Every future asteroid impact event is already an event in progress.
This note is in reply to Mike Treder’s recent article (with which I generally agree) about the threat of near-Earth objects.
Here are my responses to a few of the points made:
You’ll notice, though, that these things happen periodically; not on a regular basis, but every so often…
This seems self contradictory. Periodic means to occur at regular intervals. I think you wanted to say non-periodically, or aperiodically, or at random, without a recursive pattern. Maybe “You’ll notice, though, that these things happen; not on a regular basis, but every so often,” would have been better. However “You’ll notice, though, that these things happen ‘at random’; not on a regular basis, but every so often,” would have been best.
The reason I would pick on this semantic is that the leading astronomy ‘experts’ in this issue have seemed to come to believe in their own intellectual artifacts: population estimates, average relative frequencies, statistical probabilities, power law distribution curves, as if they were hard empirical definitive evidence and not simply academic fabrications. When portrayed to the public or government, the consequence is a gross misapprehension of the threat. Clark Chapman even recently used the phrase ‘known frequency’ in arguing against the possibility of a given large asteroid event 12,000 years ago.
I’m just sayin’, words are symbols for ideas. And here, there has never been a more critical time in the life of mankind for us to get the ideas right.
(If astronomers and aerospace engineers were as sloppy with their mathematical semantics as they are with their linguistic semantics we would still be observing the Sun as it revolved around the Earth.)
...and somewhat predictably. Most of them result from impacts of asteroids or comets. And guess what—those “planet killers” are still out there.
I don’t know what other extinction events you may be referring to here but speaking for asteroid impact events, at least in this context they are wholly unpredictable. In referencing the past occasion of these events or the systemic geometric dynamics of these objects there is no recursive pattern or potential for recursive pattern in their occasion.
The problem with predictability is that every asteroid that will ever strike Earth is already out there and already on course to strike Earth. Every future asteroid impact event is already an event in progress—there is simply nothing to predict! Which and when and how large the next one will be is a never-ending matter of seeing it coming soon enough and with a high enough degree of certainty for us to mount and effective response. The current and proposed observational efforts can only do that as a matter of very good luck.
We can state with absolute certainty that another large impactor will be on a collision course with Earth at some point in the relatively near future. It could be a hundred years from now, a thousand years, a million years, ten million years—or it could be, metaphorically, tomorrow.
Why ‘metaphorically’? Tomorrow is true, precise and literal—and as such the threat is evergreen. If we expect more money from the public and government to address this issue we must scare them better. No Fear = No Funding. No Funding = No Planetary Defense. No Planetary Defense = No More Mankind. This much ain’t rocket science… okay, maybe a little.
Thousands of near-Earth objects (NEOs) are in orbits that bring them into close proximity with the Earth. In addition, there are millions of icy and rocky objects out in the Kuiper belt, any one of which could be jostled from its orbit and sent plummeting toward the Earth at any time. It is estimated that at least 70,000 of these objects are more than 100 km in diameter, large enough to cause the next major extinction event.
Deflecting impending comet impact threats (Oort Cloud/Kuiper Belt Objects) would be virtually impossible from Earth. Perhaps from the orbit of Mars—and at 100 km, not without something a lot bigger than nukes. Probably why none of the proposed discovery surveys even try to look for comets. For now, our response to comet impact threats is the same as to the threat of Rogue Black Holes or Gamma Bursts… Hope!
FYI: At 25 meters (the floor of the threat/harm threshold) or greater, the estimated NEO asteroid population is ~10 million. And whereas extinction level threats begin at 10 km for asteroids, given their greater velocity it is only 6 km for comets.
However the number of asteroids or comets in itself is strategically irrelevant. After all, how many 10 km asteroids or 6 km comets does it take to constitute one extinction level event?
The search for NEOs can be conducted at relatively low cost, especially if it’s done on a cooperative international basis and involves government, academic, and individual volunteer efforts.
In this context you could say that seeing them coming’individually, a few decades before impact, is as close to predictably as we can get.
I trust you understand that if we are going to respond to this threat, and do so successfully, then the detection element will be only a small fraction of the cost in terms of human endeavor. And that when you say ‘relatively low cost’ it would be relative to the cost of deflection or perhaps relative to the magnitude of the loss of our species due to extinction by NEO.
To attempt to deflect a 10 km asteroid with nuclear ablation today, all things considered, would require 10,000 megatons (twice the worlds current nuclear arsenal) delivered by 1,000 Aries V (on the drawing board) heavy launch vehicles. And through 1,000 launch windows…
We can build more nukes and rockets. But even one launch window is a matter of chance and we would need 1,000 of them. If we are to succeed here we need to build and pre-position such a capability to some circumstellar orbit (orbit of Mars?) before we see it coming. And ‘before’ we see it coming begins… Now! Then we can afford to worry about comets.
(For a 100 km object multiply everything above by 1,000 times.)
Although the odds of detecting and stopping a major comet or asteroid that could threaten civilization are small, they are greater than zero, and the cost of ignoring the search is, well, potentially everything.
If you mean exactly what you say here I agree. I’m just surprised that anyone else would say it!
In other words: As things stand, our failure, so far, to develop our conceptual abilities into manifest capabilities will most likely result in a failure of any effort to respond to and deflect any extinction level threat.
However, if you were in fact somehow referring to some academic random-chance probabilistic assessment of the next extinction level event any time soon, then that would be irrelevant, strategically speaking.
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