I don’t have any idea where you pull “10M dead” from, but a 300m diameter PHO of solid rock intercepting the Earth at somewhere near orbital speed would release energy on the close order of 6 million megatons of TNT equivalent. That’s about one thousand times the total explosive yield of all nuclear weapons ever constructed. Worse yet is that it is a direct impact to the crust of the Earth which would to more and further-reaching damage than an air or ground burst of a nuclear weapon. The Chesapeake Bay impact crater is thought to have been caused by a bolide that was 100-150m across, and it is believed to have disrupted the geology, hydrology, and local climate of the area for decades following the impact. If such an impact were to occur in this location today, it would devastate the Eastern Seaboard, killing tens of millions of people, displacing any survivors, and wreaking trillions of dollars in economic lost. There is no conceivable scenario save for fragmenting such an object without displacing it–which may occur anyway if it is, like many space objects, several smaller rocks of still-catastrophically hazardous size cemented together–that would be worse than doing nothing. The degree of devastation this would cause is quite simply unimaginable by our monkey brains; it would make any natural terrestrial catastrophe like an earthquake, tsunami, or hurricane look like a day in the park by comparison.
It’s going to suck if it does hit, but I’d actually lay money on there being less than ten thousand casualties, simply because we’ll be able to evacuate people. For most of the projected impact track it’s either over the ocean or over largely unpopulated land and you can bet your boots that the impact zone will be calculated very precisely indeed nearer the time. Completely evacuating the Hawaiian islands could be interesting, though.
Upon what possible basis or professed expertise do you lay such a claim?
900 feet; ~ 300 meters. (270 meters, actually, but at these magnitudes a 10% error is the difference between trampled by an elephant or a hippopotamus.)
Yes - but which is it? It looks like **Quartz **was talking about an object 300 feet across striking the Earth (510 Megatons/10M Dead), and you’re talking about an object 300 meters striking the Earth (6,000,000 Megatons).
A second vote for playing with this calculator and seeing for yourself what the effects will be.
Entering Apophis’s stats (from its Near Earth Object Risk page at NASA, and taking the worst-case scenario (all iron composition, 90 degree impact angle, rounding up slightly on the size and speed) and I get an impact with a KE of, ballpark, 1.65 Gigatons. Not fun, but not an utter global catastrophe. According to the calculator’s researchers, we get smacked by something like this about every 100,000 years or so. Looks like the tsunami is going to have the widest ranging effects, and be the big killer, unless you’re within ~50 miles of the impact. (Or it hits land.) Hilo’s going to have a hard time, yet again…
The impact calculator model shows very little heat pulse/fireball from a bolide with 13 km/s velocity, and playing around with the model before made me think that heat was one of the primary killers from these kinds of impacts. Another peculiarity of the calculator is that it suggests that pulverizing the rock ahead of time into smaller rocks less then 25 m across renders the bolide mostly harmless.
(More of the K.E. goes into heating up the atmosphere than moving rock or water. Yes, the atmosphere is going to heat up a LOT when you smack it with 10^19 Joules. As an extremely rough calculation, just taking all of the KE and making it heat up the atmosphere for a 100 miles around and using 1.3 X 10^-3 Jcm^-3K^-1 (my kingdom for superscripts and subscripts!) for the heat capacity of air, I get around a 0.5 degree C rise, for the entire atmosphere within 100 miles)
But Apophis is a totally different sort of critter than, say, the separate impactors of Shoemaker-Levy. OTOH, it’ll be a lot easier to move Apophis than it would have been to move Shoemaker-Levy, should the need ever arise.
For Stranger’s 6 million Megaton equivalent K.E., according to the calculator, you’d need something like a 2 mile wide comet, moving at typical cometary speeds (30 miles/second). That would be extremely bad. Thankfully, it only happens every 20 million years or so.
The article linked by the o.p. says “The Russian scientists are basing their predictions of a collision on the chance that the 900-foot-long (270 meters) Apophis…” The Wikipedia article also indicates a “dimension” of 270m (not clear if they mean longest dimension, or average, or what). I just hazarded a guess about density and intercept speed to get a rough order of magnitude estimate. Even if 510 MT is an accurate estimate, that is still an order of magnitude larger than the largest nuclear explosion, and unlike the Tsar Bomba (which was an air burst) this would be a surface impact that would have a major seismic response. Pretty much the only way it would not destroy several major metropolitan areas in Europe, Asia, or South America is if were to land in mid-ocean and the impulse were absorbed and distributed by the ocean before the wavefront hits a continental shelf. This is a massively larger catastrophe than anything experienced in human history.
You still haven’t read the cited articles, have you?
Look at the expected impact map. It’s unlikely to hit anywhere near any major population centre unless it hits Central America. Russia is largely unpopulated. The Pacific is sea. And if it’s going to hit, we’ll know where well in advance and so evacuation plans can be put into effect.
I wouldn’t be blase about the energy of this thing. At 500 MT to 1,500 MT, (and which figure’s applicable depends on the density of this thing, it’s exact size, and exact impact velocity: none of which I’m confident in to ± 10%, and the density could be a factor of 2 either way.) it has comparable energy to the Tambora eruption, and is anywhere from 3 to 8 times the Krakatoa explosion. Both of those were, I thought, the previous biggest BOOMs in recorded history. I guess you can count Thera, for a given value of “recorded”. For sustained fury, it’s enough energy to power a large tropical cyclone for about 1/2 day. It’s going to be a really big bang wherever it hits. And even if people are evacuated in time, the tsunami is likely to break lots of stuff.
Yes, I read the fucking links, obviously with more care than you did. The supposed land track assumes that the impact falls along the rotational centerline of the Earth with its aspect. The reality is that it could fall anywhere above or below the normal to that line and still impact the Earth with roughly equal probability, even if the particular time interval of impact is correct and the PHO remains intact. The ±3σ bounds around that land track are clearly much larger than the diameter of the Earth (judging by the low probability of impact). A 510 MT TNT-equivalent impact would be about the same as a 7.0-7.1 earthquake on the Richter scale; enough to wreak destruction over hundreds of kilometers. Were it to landfall in or off-shore of a major metropolitan or industrial area it could easily kill tens of millions of people and destroy hundreds of billions or trillions of dollars of real estate, which is enough alone to justify an attempt to redirect it.
It depends on where it hits, but in general, no. Volcanoes generally occur either at the overlap of tectonic plates or over an upwelling diapir (hotspot or plumes in the lower and upper mantle that put pressure on the middle of the plate). An concentrated impact may possibly cut through to the mantle, but unless there is substantial pressure from below it will probably fill in and cool in a lava dome without forming the cinder cones or stratovolcanos that we typically think of as volcanos. Something large enough to really blow a big hole in the crust and create enough pressure to force upwelling in the mantle is going to create a shock wave that’ll destroy a good portion of the continent it hits, i.e. the Chicxulub Crater. This type of impact is an extinction level catastrophe, and the object that caused it probably couldn’t be redirected by any practicable method using an extension of existing technology.