After Last Week We Can Truly Say The Asteroid Peril Isn't just Science Fiction

Image of the Chelyabinsk asteroid's exploded trail  over Chelyabinsk, Russia,  in 2013.

An interesting article by Gordon L. Dillow ('The Asteroid Peril Isn't Science Fiction', WSJ, p. C4, July 6-7) appeared barely two weeks before a real asteroid scare, which few humans may know about. This near hit concerned the asteroid 2019 OK  which was definitely not "ok" in terms of its near collision with Earth.  This is also given  no one picked it up until it had already passed.

Alan Duffy  - lead astronomer at the Royal Institution of Australia-   was  particularly confused in the aftermath.  This was given  a couple of forecasts had already predicted a couple asteroids were to pass close to the Earth  last week.   So, in Duffy's mind, everyone was getting hysterical over something already known to be coming, but evidently not. Because most did not know as 2019 OK whizzed past Earth.

That led Duffy to say:

“I was stunned.  This was a true shock.”

Indeed.

So what happened and why wasn't it on more astronomers 'radars' so to speak?  According to Michael Brown - a Melbourne-based observational astronomer- this particular beast wasn't one that astronomers had been tracking. And it "seemingly appeared from out of nowhere". 

Let's back up here. By 'out of nowhere' he means from the direction of the Sun which of course will obscure any relatively small rock headed for us. In this case, we're talking of an object weighing in at nearly  6 x 10 14  kg and wider than an NFL football field. The trouble is, as Gordon Dellow's article makes clear, there are "hundreds of thousands of other near Earth asteroids both large and small which up to now haven't been identified." If they haven't been identified that means we don't have their orbital elements and hence can't predict what tracks they will take, including how close to Earth in the future.   The other not so sanguine news?  The funding allocated for asteroid defense this year is barely 1 percent of NASA's total budget of $21.5 billion.

Certainly, before planing expeditions back to the Moon and Mars we ought to be shoring up our defenses against oncoming asteroids that could wipe out whole cities - or islands - no?

Our previous asteroid wake up call occurred with the  Chelyabinsk object (est. 66 feet in diameter)  that blew up over that Russian city in 2013.  That event was energetic enough to injure over  1,000 people by flying debris as the shock wave from the explosion swept across the Russian city, shattering windows and leaving a trail of damage.  The explosion was estimated to have had a force greater than 30 Hiroshima atomic bombs, according to NASA scientists.  

By contrast, the object that just missed us would have been in the 1- 2 megaton energy range and had it struck a city like New York or Philly, would have incinerated it, reduced it to ashes. If it had struck Barbados, as I pointed out to Janice, it would have flatted that little 21 by 14 miles island. 

According to data from NASA, the craggy rock was large, an estimated 57 to 130 meters wide (187 to 427 feet), and moving fast along a path that brought it within about 73,000 kilometers (45,000 miles) of Earth. That’s less than one-fifth of the distance to the moon and what Duffy considers “uncomfortably close.”

“It snuck up on us pretty quickly,” said Brown, an associate professor in with Monash University’s School of Physics and Astronomy. He later noted, “People are only sort of realizing what happened pretty much after it’s already flung past us.”

Not good enough my Astro friends!   The asteroid’s presence was discovered only earlier this past week by separate astronomy teams in Brazil and the United States. Information about its size and path was announced just hours before it shot past Earth, Prof. Brown said.  He added:

“It shook me out my morning complacency. It’s probably the largest asteroid to pass this close to Earth in quite a number of years.”

So how did the event almost go unnoticed?  “Nothing this size is easy to detect,” Duffy said of Asteroid 2019 OK. ″You’re really relying on reflected sunlight, and even at closest approach it was barely visible with a pair of binoculars.”

Brown said the asteroid’s “eccentric orbit” and speed were also likely factors in what made spotting it ahead of time challenging. Its “very elliptical orbit” takes it “from beyond Mars to within the orbit of Venus,” which means the amount of time it spends near Earth where it is detectable isn’t long, he said. As it approached Earth, the asteroid was traveling at about 24 kilometers per second, he said, or nearly 54,000 mph. By contrast, other recent asteroids that flew by Earth clocked in between 4 and 19 kilometers per second (8,900 to 42,500 mph).

Regarding the elusive 2019 OK object, Prof. Brown went on to say:

“It’s faint for a long time.  With a week or two to go, it’s getting bright enough to detect, but someone needs to look in the right spot. Once it’s finally recognized, then things happen quickly, but this thing’s approaching quickly so we only sort of knew about it very soon before the flyby.”

Basically summarizing why we desperately need thousands, hell, millions, more asteroid detection volunteers with basic astronomy principles guiding them and the telescopes needed for the job.  Such an instrument would be along the lines of the Celestron-14 shown below:

Ironically in May, barely two months before the close pass of 2019 OK, a hypothetical  asteroid impact exercise had been conducted.   This was as part of the International Academy of Astronautics Sixth Planetary Defense Conference held in College Park, MD.

As described by Dellows (ibid.) the exercise began when astronomers in Hawaii detected an 800 foot wide asteroid they dubbed 2019 PDC.  In other words, roughly twice the maximum estimated diameter (427' )  of the actual 2019 OK that just brushed past us.   The decision of the team was then to try to "reduce its speed by a tiny fraction" using missile "kinetic impactors".   Then:  "By the time it reaches its predicted rendezvous point with Earth, our planet will have already moved in its orbit."  All well and good, right?  Not really, as Dellows continues:

"Three of the impactor ships smashed into the asteroid.  The main body was destroyed and would miss Earth.  Denver (the original target) was saved. Unfortunately, one of the kinetic impacts inadvertently broke off a 200-foot wide chunk of the asteroid - and that hurtling fragment was now on track to hit New York City,"

Let's pause here to point out the size of the fragment was smaller (by up to a factor 2)  than the estimated size of 2019 OK that just missed Earth.  Anyway, as we read on (ibid.):
"The only hope was to destroy the fragment with a nuclear device.  But existing ground -launched nuclear missiles were not designed to take on an asteroid.in space and there wasn't time to launch a nuclear armed device to intercept the asteroid chunk.  New York would just have to take the hit."

So what was done in the exercise?

"Millions of people were evacuated.  The asteroid exploded in a fireball over Central Park.- and Manhattan was wiped off the map."

Two takeaways:  First, at least the exercise saw a partial success in that the population of Manhattan was evacuated in time, though they had nothing to return to but ashes. Second, The much larger REAL asteroid that appeared last week, and would have REALLY destroyed Manhattan (or Barbados) missed us by an astronomical hair's breadth.

The consolation? "The chances of a civilization- destroying asteroid are exceedingly small".  Well, true, but they are not zero.  After one hit in 2013 and another near collision this month, I suspect it's time we get a real plan in place especially for these smaller, city-killer asteroids that emerge at the last minute.    As Dellows ends his piece:
"It isn't a question of whether humankind will have to confront the prospect of a destructive asteroid hurtling our way; it is only a question of when."

Let's hope that 'when' is still a long, long time away.

See also:

A Proposal to Eliminate Smaller Asteroid Threats - Brane Space

brane-space.blogspot.com/2013/03/a-proposal-to-eliminate-smaller.html

Small Asteroid Early Warning And Targeting Just Got Real With Passage of 2012 TC4

Image of the Chelyabinsk asteroid's exploded trail  over Chelyabinsk in 2013.

Who could forget the passage of the Chelyabinsk small asteroid as it passed over the city by that name in central Russia in February, 2013? The event was energetic enough to injure over  1,000 people by flying debris as the shock wave from the explosion swept across the Russian city, shattering windows and leaving a trail of damage.  The explosion was estimated to have had a force greater than 30 Hiroshima atomic bombs, according to NASA scientists, and the shock wave was so powerful it travelled twice around the world.

As reported in Physics Today (Sept., 2014, p. 32) the object has now gone down in infamy as being 20 m (66 feet)  diameter, entering the Earth's atmosphere at 19 km/s.   Based on a 3-dimensional simulation using a shock code developed at Sandia National Laboratories (originally intended to model nuclear explosions). the Lab's supercomputer showed that the Chelyabinsk blast was at least a half megaton, or comparable to the yield of many U.S. warheads on ICBMs, like the 'Minuteman'.

Scandia Lab simulation panel for Chelyabinsk event.(From Physics Today, Sept., 2014)

Some of the ancillary information and insights that the Sandia team has assembled with other data:

- The entry at 19 km/s meant that it originated from the asteroid belt between Mars and Jupiter - not from a ballistically launched missile whose velocity would only be about 11.2 km/s or a short period comet with a mean speed of 35 km/s.

-  The altitude of the blast indicated the object was small and weak. The diameter of 20 m (66 feet) was estimated base on the observed velocity factored together with the assumed density of the material.

- The asteroid first felt the presence of Earth's atmosphere while it was thousands of miles above the Pacific Ocean and for a dozen minutes the 10,000 ton rock fell swiftly and unobserved passing at shallow angle through the atmosphere where the molecular mean free path was much greater than the 20 m diameter.

- When it crossed over the border into Russia at 3:20:20 UT and was 100 km in altitude 99.99997 % of the atmosphere still lay beneath it.

- For the better part of 10 seconds the asteroid hurtled through the air as a rigid body moving at a shallow angle, 17 degrees relative to the horizon and descending 1 km for every 3 km of flight.

- At about 45 km altitude the entry dynamics began to change. The dynamic pressure then built up from 0.7 Mpa (millions of Pascals, where 1 Pa = 1 atm equivalent), Within a couple more seconds, below 40 km, pressure on the now fracturing asteroid increased past 1 MPa, breaking it into a number of smaller fragments.

- As the pressure then grew exponentially the process cascaded and formed ever smaller fragments that rapidly increased the surface to volume ratio. As the fragments ablated the hot gas between them built up finally resulting in a chain reaction and a massive explosion converting the asteroid's kinetic energy into heat and pressure (yielding the shock wave that shattered windows).

All of the preceding is again relevant as learned of the recent close passage of the small asteroid 2012 TC4 over Antarctica  at a too close distance of 27, 200 miles. TC4 was estimated to be travelling through space at roughly 16,000 mph - 4.5 miles a second.


Artist's conception of 2012 TC 4 passing in vicinity of Earth.

2012 TC4, was first spotted five years ago by the Pan-STARRS telescope at the Haleakala Observatory, in Hawaii, before disappearing as it orbits the sun. It then reemerged in July on a trajectory well inside our lunar orbit.  A sketch of the object's trajectory is shown below:

Depiction of the trajectory of 2012 TC 4 on Oct. 12.

Observations reveal that 2012 TC4 is an elongated and rapidly rotating object that has been known to make many close approaches to Earth in the past. The space rock orbits the sun approximately every 1.67 years at a distance of about 1.4 AU. Astronomers estimate that 2012 TC4 has a diameter between 26 to 85 feet (8 to 26 meters).   Note the size which is near the diameter range of the Chelyabinsk object. In other words, had TC 4  entered the Earth's atmosphere it could have delivered a similar air blast to that arising from the Chelyabinsk object.

Thankfully, TC 4's approach was planned for in advance as a test object for an asteroid early warning network - something I've been harping on for over three decades.  Thus, long before it got within a tenth of the Moon's distance NASA had planned to use the flyby to test early warning for incoming space rocks.  Observatories world wide - part of the International Asteroid Warning Network - had been focused in an TC 4 for weeks to test communication and coordination.

Before this close pass, researchers had relied on "tabletop" tests - or computer simulations with no actual asteroids involved.   These sort of simulations make for nice abstract exercises but don't deliver much in terms of real time, actual asteroid threat factors.

What still remains is how one of these beasts might be stopped say if it's trajectory was determined to be headed for New York City, or New Orleans.  Back in March, 2013 I noted the development of  a high-powered 50kW laser by a German firm (http://www.dailymail.co.uk/sciencetech/article-2259639/The-groundbreaking-Star-Wars-laser-shoot-drone-sky-TWO-MILES-away.htmlIt had the power to knock down a drone from two miles away, and cut through a steel girder from 1kilometer away. Yet it was accurate enough to hit a target the size of a mortar round which got me to thinking of using multiple similar lasers in an effort to deflect small (< 50m dia.) asteroids. These would be similar to the Chelyabinsk object that recently exploded over central Russia. The German defense firm Rheinmetall Defence that developed it – could conceivably get its name in lights.

Think then of several Russian and U.S. craft carrying these devices to intercept an oncoming small (‘city buster’) asteroid before it can wreak havoc. If the detailed effects and dynamics can be worked out before hand, I see no reason why the oncoming threat can’t be stopped. Or, would we rather spend $20 billion more on missile “defense” systems that have been shown to be useless?

After the close pass of 2012 TC 4 this becomes much more than an abstract, academic exercise. The recent encounter shows me that it is crucial we not only be able to confidently track small asteroids, but also come up with ways to destroy them - say if one is bearing down on a major population center.

As the hackneyed phrase goes, "if we can send men to the Moon and back......."/

Asteroids: The Celestial 'Swords of Damocles'

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Nearly forty years ago, my article on Earth -impacting asteroids ('Target Earth?') was published in the Barbados NATION newspaper, not long after I'd completed my Peace Corps service. For many citizens of the island nation it was the first time they'd ever been awakened to a potential threat from space.(Ten years later a more direct wake up call would arrive with the impact of a large (~ .5m wide) meteoroid in what became known as the "Mount Tenantry event" - which I helped investigate.

As I noted in my article the most worrisome class of asteroids were precisely the "celestial swards of Damocles" or Earth-crossers, otherwise known as Apollo objects.  How big a threat are the Earth-crossing asteroids?

First,  it is instructive to see how they can emerge as a threat when their orbits are perturbed as shown in the sketch above, e.g. for the asteroid known as Icarus.  What makes any large asteroid dangerous, is its mass in combination with its relative velocity or speed of approach. Thus, large Apollo objects (and other asteroids) would typically have relative velocities from 11,000 to 30,000 meters per second, or about 6.8 to 19 miles per second.

For an asteroid with a 1 kilometer (0.62 mile) diameter, at a density three times that of water, this would generate an equivalent energy on impact of one million Hiroshima sized atomic bombs. Since the Hiroshima explosion was equivalent to 13,000 tons of TNT, this means a larger asteroid would generate an explosive force of 13 thousand megatons. This already is roughly equal to the total equivalent of all U.S. nuclear warheads.

For a ten kilometer asteroid (roughly 6 miles across) the explosive equivalent would translate into 13 million megatons. This would dwarf all man-made nuclear stocks and warheads, and is rightfully called ‘planet –killer’. An asteroid about this size is believed responsible for the extinction of the dinosaurs nearly 65 million years ago. For present day inhabitants of Earth, the consequences would hardly be less startling or grave. A Gaspra (12.5 x 7 x 7.5 miles) impact would obliterate all life on Earth - never to arise again. On the Torino scale, which registers the magnitude of asteroid devastation we are talking about a Torino scale 9 - the maximum.

                                                 The asteroid Gaspra - A planet killer

The crater and blast effects alone would eliminate most of the population on the continent it struck. An ocean strike, creating tidal waves upwards of 2 miles in height, would be even worse. The debris, for its part, would block out most solar radiation for years and probably usher in massive extinction of plants-  including sea plankton – that account for ninety percent of our oxygen.


How probable is such a Torino 9 asteroid impact?

The calculation of the probability is based on an estimated 15 Apollo Objects acquiring an Earth-crossing orbit every million years. From this it has been reckoned that the odds of a given Apollo Object eventually hitting Earth are 5 in one billion. This works out to one impact, on the average, every 200 million years. But wait. There are about one thousand such objects in all so that the probability that any one will strike Earth is now: (1000) x (5/1000000000) = 5/1000000. This figure: 5 in one million means that time wise, 5 asteroids would be expected to strike Earth every million years, or one every two hundred thousand years.

The problem with statistics like this is that they can lull a person into a false sense of security. It is true that the impact rate is low, relative to the scale of recorded history, but it is comparatively high in the context of geological time (thousands of millions of years). To fix ideas, consider that the most recent crater formed by a true Apollo object (as opposed to a large meteoroid) is at Lake Bosumtwi basin in Ghana, Africa. This is about 1.3 million years old. On this basis, the Earth is certainly long overdue for another hit of staggering proportions. Indeed, from the mean frequency of collisions we have worked out, the Earth should have been struck at least six times since the last impact by an Apollo object.

I should point out that in all of these statistics no account has been taken of the colliding comet factor. However, estimates by the Ames Research Center suggest that- with comets included - there are at least 2,000 objects that can cross the Earth's path. (Recall the captured 1994 impacts on Jupiter were from a large comet). Since my calculations were based on 1,000 objects - e.g. asteroids only, the probabilities would increase by a factor two. The time interval between major collisions would be halved.

Of course, statistical behavior does not follow rigid rules. There is no statistical law that pre-ordains an asteroid impact on Earth with the precise regularity of a 200 thousand year interval. By analogy, there is absolutely no reason why I shouldn't get a run of heads if I flip a coin ten times. Maybe I will get six heads in a row in one such run. The point, and it is an important one, is that the string cannot continue indefinitely. Assuming the coin is "true" the probability of heads must average 1 out of every 2 tosses. Looking at 100 tosses, for example, the total heads and tails will probably be very close to 50 each. The run of heads at some stage would have been compensated for by a similar run of tails to balance out the "law of averages".

Somewhat similar conditions apply to asteroid strikes on Earth. The run we are currently experiencing: no major hits over 6 successive periods of two hundred thousand years each, can’t go on indefinitely. As certainly as heads become tails for coin tosses, "no impacts" must become registered impacts for Apollo objects approaching Earth. The next big hit could come at any moment from an undetected asteroid. Or, it may come in the year 2036 (April 13, to be exact)  when the near Earth asteroid  99942 Apophis that some forecasts have now assigned a 2.7 in 100 chance of striking Earth. Fortunately, even if such an impact occurred, the destruction would be localized, given the object's 325m diameter.

This highlights the reality that there are millions of smaller, less visible or less detectable objects, that can also wreak havoc.  Few may recall, but as recently as February, 2013,  our Earth faced not one but TWO cosmic shots over our planetary bow.

The first shot - now known as the Chelyabinsk object- occurred with the explosion of an 11 ton (~2.2. x 10 ⁴ kg) meteoroid over the Russian Urals creating an airburst over Chelyabinsk, Russia  The blast broke windows in 6 cities according to an MSNBC report the morning of Feb. 15, and injured 1,000 people, while 3,000 buildings sustained damage mostly from the blast shock wave.

Some 3D simulations and analyses at Sandia National Laboratories in 2014 showed the following about the object, actually since designated a small asteroid:

The entry at 19 km/s meant that it originated from the asteroid belt between Mars and Jupiter - not from a ballistically launched missile whose velocity would only be about 11.2 km/s or a short period comet with a mean speed of 35 km/s.

-  The altitude of the blast indicated the object was small and weak. The diameter of 20 m (66 feet) was estimated base on the observed velocity factored together with the assumed density of the material.

- The asteroid first felt the presence of Earth's atmosphere while it was thousands of miles above the Pacific Ocean and for a dozen minutes the 10,000 ton rock fell swiftly and unobserved passing at shallow angle through the atmosphere where the molecular mean free path was much greater than the 20 m diameter.

- When it crossed over the border into Russia at 3:20:20 UT and was 100 km in altitude 99.99997 % of the atmosphere still lay beneath it.

- For the better part of 10 seconds the asteroid hurtled through the air as a rigid body moving at a shallow angle, 17 degrees relative to the horizon and descending 1 km for every 3 km of flight.

- At about 45 km altitude the entry dynamics began to change. The dynamic pressure then built up from 0.7 Mpa (millions of Pascals, where 1 Pa = 1 atm equivalent), Within a couple more seconds, below 40 km, pressure on the now fracturing asteroid increased past 1 MPa, breaking it into a number of smaller fragments.

- As the pressure then grew exponentially the process cascaded and formed ever smaller fragments that rapidly increased the surface to volume ratio. As the fragments ablated the hot gas between them built up finally resulting in a chain reaction and a massive explosion converting the asteroid's kinetic energy into heat and pressure (yielding the shock wave that shattered windows).

- Only one significant piece-fragment remained post-explosion. This continued to fall like a ballistic missile in 'dark flight' at terminal velocity until it punched through the ice of frozen Lake Chebarkul.  This 1.5 m diameter boulder thereby became the largest Chelyabinsk object found.

As noted by one of the simulation authors, reported in Physics Today, September, 2014 (p. 35):

"In Chelyabinsk, the energy deposition that led to the explosion took place in stages and was spread out over a long distance because of the shallow entry angle. Energy was deposited at linear densities greater than 1 kiloton per kilometer and rose to a peak of 80 kt/km; most of the energy deposition occurred at altitudes from about 38 km down to 23 km. It took four seconds for this to happen during which the asteroid left a 50 km wake of hot expanding gas and ablation products."

The incident recalled for many the Tunguska Siberian event in 1908 which knocked down nearly 80 million trees and decimated nearly 820 square miles, about two-thirds the size of Rhode Island.  And this was from an object perhaps ten times the size of the 11 ton meteoroid that just hit the Urals this morning.

Meanwhile, on the same date, a much larger asteroid, the one identified as DA 14 2012, appeared .:

The trajectory of 2012 DA 14 passing close to Earth.

 It packed a mass of 130,000 metric tons (~ 2.9 x 10⁸  kg) and potential for an explosive release equivalent of a 20 megaton nuclear bomb.  Incredibly, the object was first discovered back in February, 2012  by a DENTIST using a high powered telescope. Why had no national scientific agencies made the discovery? What would have been the case if,  instead of a minor midget asteroid making this close pass, it was a planet killer 6 km across or larger? (As opposed to only 150'  or 45 m  DA 14 2012) Would we be ready to do anything other than piss, moan and pray?

Projects Space Watch and Spaceguard remain on funding life support, though a bit more largesse has come through in recent years. But mainly, asteroid tracking is the work of unsung, unpaid amateurs..Space Watch , had been based at the University of Arizona, and featured generous grant allocations in its early years when it  discovered over 1,300 approaching asteroids by 2002..  Later, as the austerity mindedness infected all science research areas, that capability  wound down a lot. Especially since the GOP takeover of the House in 2010, so. amateurs took over more of the load.  Not that the latter aren't observationally capable, but we also need professionals to spot these things and then (using the well known equations of celestial mechanics)  obtain the orbital elements as fast as possible. -.

Spaceguard extends asteroid detection to focus more on NEOs (near Earth objects) as opposed to singling out near Earth asteroids (NEAs).  Again budget limitations have loomed and imposed  truncated observation time frames and selectivity. Although there have been many discoveries of near-Earth asteroids  the Spaceguard Project has been criticized for not having an in-depth master plan if our humble planet is directly in the crosshairs of a giant asteroid. It has also been criticized of having false alarms that could lead to dangerous implications.

NASA published an article in April of 2001 to clarify many questions that have come up with this project. The report distinguished the difference between NEOs and NEAs, why the organization selected NEAs with a diameter of at least one kilometer in diameter, why the number of 90 percent was chosen and many other questions that have perplexed the general public.

Astronomer Paul Chodas, who works in NASA's Near-Earth Object program in Pasadena, Calif., decribed the Russian object as:

"....a tiny asteroid.  It would be very faint and difficult to detect — not impossible, but difficult."

Meanwhile, the actual asteroid DA 14 2012 that made a heart stopping close pass, was three times the size of the Russian object, and coming in at nearly 40,000 mph. Its blast -energy release was more like a 20 megaton blast.

Neither Space watch or Spaceguard is adequately funded, which means that either an NEO or NEA can escape through the observational 'net' and could wreak havoc, especially if the size and mass approaches that of the object that created the Barringer crater in Arizona, e.g.

The crater was formed by the impact of an iron-nickel object  50 m (165') across, coming in at 28,600 mph, generating an impact energy of 10 megatons. This crater, in other words, would have reduced a city the size of Boulder, CO to rubble. The impact occurred roughly 50,000 years ago. By comparison, the meteoroid that exploded over Russia was about 49 m in diameter, and Russian physicists estimate its explosive release at about 20 Hiroshima bombs of 10 kilotons each, or 200 kilotons - thus, a fifth of a megaton. Small change, in other words.

.Most disturbing , there is no formal, well-funded program or plan - of which anyone is aware  - for taking out a planet killer - say 6-10 km across, if one does target Earth. There have been past ruminations about using nuclear weapons to try to split the object into smaller pieces, but that was put aside when the ''architects" decided a number of smaller (1 km ) strikes might not be so good either. But still, a planet killer of 6 km arriving intact is not something to dismiss lightly and our space gurus may well have to opt on the side of losing half of the earthly populace to losing ALL of it, say from a nuclear winter onset as a result of some 10 ²⁸ kg of dust and debris in our atmosphere, cutting off sunlight

The worst nightmare is the Earth-sterilizing asteroid or "planet killer", with explosive equivalent of > 100,000 megatons. This will be from a rock greater than 10km across.  Some of the Torino scale levels and gradations (registered by mass and velocity) are as follows:

i) Regionally devastating impact, e.g. June 30, 1908 Tunguska impact. Devastation range approx. 10,000 sq. kilometers, killing crops, humans, animals.

Size of object: 20 m (~ 66') to 100m (~330') diameter .

Explosive release: 1 Megaton to 100 megatons TNT equivalent. Collision probability between ~ 1 in 100 yrs. and 1 in 1000 yrs

ii) Mass extinction impact: e.g. KT-boundary impact of 65 million years ago . Devastation range ~ 10 million sq. km., killing all extant dinosaurs and hundreds of other species.

Size of object: 100m (~330') diameter to 1 km (3330') dia.

Explosive release: 100 Megatons to 100,000 megatons TNT equivalent.

Collision probability: between ~ 1 in 1000 yrs. and 1 in 100,000 yrs.

iii) Earth Sterilizing Impact: Example......not yet. ("Black swan" territory? Errrrr.....no.)

Would annihilate every last species on the planet, and sterilize it for thousands of years to come. Devastation-affected area: > 50 x 10^6 sq. km.

Size of object: >> 1 km (3330') dia. (Likely source: any of one hundred Apollo asteroids whose orbits intersect with Earth's)

Explosive release: >> 100,000 megatons TNT equivalent.

Collision probability: Unknown but at least one asteroid specialist (Dr. Basil Booth) has predicted an Apollo asteroid collision some time in the next 250,000 yrs.

As one sees by surveying the preceding, this asteroid falls about midway into the "Mass extinction impact" range. In other words, if it struck the Earth, we'd be looking at a serious disaster indeed, whether water or land strike.

When my NATION article was published many readers in the aftermath asked: "How can any scientists actually know that one of these things could hit  us?" 

My answer - then and now  - is that these specialists (planetary astronomers)  make use of the highly precise branch of astronomy known as celestial mechanics. Especially that branch that has the objective of obtaining the perturbations which an astronomical object is likely to experience under the combined influence of the gravitational forces of other (e.g. larger, more massive ) objects acting upon it


While it is true that the probability of a monster rocks smacking us appears remote it ought not be too readily dismissed. This is because one never knows what sort of gravitational perturbations can affect existing orbits. We already know, for example, that an estimated 1,000 asteroids are perturbed from the asteroid belt each year to become Earth-crossers. A select subset of these are among the planet killing or mass extinction types. The smaller ones? Yes, they are nuisances, but we can deal with them if we have some long range planning wherewithal combined with alert observers.

And what are our illustrious politicos doing in the meantime?  Following the Chelyabinsk event in 2013, Rep. Lamar Smith, R-Texas, then chairman of the House Science, Space and Technology Committee called for a hearings "in the coming weeks". In his words:

"These events are a stark reminder of the need to invest in space science,"

Yes indeed, but we need a lot more than hearings. We need lots more technically-minded people with eyes on the skies.  Investing in their time, especially for professionals with the capability of computing orbital dynamics, takes money. Their services don't come free nor should we expect that.

Astronaut Rusty Schweickart, meanwhile, advised that NASA launch a $250 million-a-year program to survey asteroids and work up a deflection plan. The latter would be most effective for the lesser objects but may also help with the larger ones, of at least mass extinction scale. Ideally Russia and the U.S.  would combine their resources and work together for the planet's benefit - as opposed to more opportunistic war -making (to ramp up defense budgets), including endless stupid wars on terror.

Up tp now nothing has been done about this.  Schweickart noted at the time that "NASA now has $20 million" for searching out these potential cosmic  terrors, and added ... "It's peanuts."

Sadly, it may well take a monster meteoroid or small asteroid (like DA 14 2012) crashing into a populated area before NASA and other agencies, and especially our tightwad politicos,  wake up. That would then be our cosmic 9/11 and prompt us to get off our asses before the really BIG one arrives. Aka, the planet killer!

Incredibly, humans have mocked the fate of those dinosaurs extinguished in the wake of the Chicxulub   impactor event 65 million years ago, but we ourselves have basically done nothing to enhance our own survival chances - should an Icarus-scale asteroid impact. Maybe it's time we seriously begin paying some attention to those celestial "swords of Damocles", large and small.

Real Fears & Bogus Ones: Telling the Difference

It  is a matter of observation that our society is awash in fear and the selling of fear. Look on the news programs any given night and you will see it staring back at you and blabbering nonstop – from the latest ISIS beheading outrage, to the latest terrorist bomb attack overseas, to the latest food contamination scare, or some manner of horrific crime committed on a college campus.

 It’s all there and designed to be fright-inducing because, well,  this is what the corporo media networks are all mostly about: stoking the fire of collective fear. According to sociologist Margee Kerr from her upcoming book, Scream – Adventures in the Upside of Fear: 

“The media  loves to tap into the fear response because it doesn’t engage with the rational mind.”

Which is true. Interestingly, from a meta-perspective, this should place watching TV News at the top of the most insidious sources of long term, free-floating fear. Both Douglas Rushkoff (‘Life, Inc’.) and Benjamin Barber (‘Consumed’) have also warned how the news tends to be delivered in bits or  sound bites with little or no analysis, explanation or clarification –all of which reinforces fear.

If I had to put the number one long term, rational fear out there it would be  the influence of the corporate media (including the print media) on vulnerable brains, i.e. those lacking a good critical thinking antidote. And yes, it’s that big a deal! Americans lacking this antidote have in the past 12 years: 1) been drumbeaten into accepting the Iraq invasion, 2) been drumbeaten into believing Saddam was in league with al Qaeda, 3) been drumbeaten into retreating from acceptance of climate change caused by humans and 4) been manipulated into retreating from earlier convictions that the Kennedy assassination was a conspiracy.

Indeed, in 2007, a resident ass ensconced at The New York Times actually wrote in the Book Review section (after bellyaching about the latest book):

"These people should be ridiculed, even shunned! It's time we marginalized Kennedy conspiracy theorists the way we've marginalized smokers."

Well, pardon me, but this certified nincompoop shows just how dangerous holding an influential media position can be when the person is a know-nothing moron. An uneducated, lazy moron who probably has never even seen one of Oswald’s CIA files!  But this points up why I regard the American mainstream media as a loose cannon that needs to be feared if one is not fully armed with critical thinking. 

Other long term fears in what I regard as order of priority include:

-         Climate change disasters, local and global (e.g. loss of coastal areas due to sea level rise)

-         The re-appearance of diphtheria, measles, whooping cough and other preventable diseases by anti-vaxxers.

-         The failure to muster funds to find a cure (or at least workable treatment) for Alzheimer’s disease – which number of cases is expected to hit 14 million by 2050 and over one trillion dollars lost in productivity, life quality, time taken off by caretakers – not to mention medical costs.

-         The failure to seriously address the threat of moderate-sized asteroids such as the Chelyabinsk object that struck Russia two years ago. One single asteroid of that size, aimed at New York City, could take it out along with 8 million people. (The odds of one hitting are 35 times more than for a large asteroid).

Now, what about more immediate fears that all rational people ought to have? I list some of these as follows:

-         Eating too much saturated fat – i.e. in burgers, pizzas, and destroying one’s cardiovascular system in the process.

-         Not getting adequate sleep before getting in one’s automobile.

-         Texting while driving, or even walking.

-         Overusing social media (e.g. Twitter) to the exclusion of reading actual books or conversing live with actual people   - thereby risking permanent brain rot. (See also the book, ‘The Dumbest Generation’)

-         Not sufficiently protecting your identity or your credit, thereby enabling its theft – especially identity theft.

This would not be complete without listing the bogus fears that occupy too many today, but which are less grave in relation to the ones above.

-         Serial killers, pedophiles (the risk that you or your child will be a victim is ten times less than the chance a medium –sized asteroid will strike, or 1 in 333,000

-         Mercury in fish, e.g. tuna – all overblown by the fear mongers, I eat solid white albacore tuna at least 12-13 days a month (the rest of the time salmon).  Mothers- to- be should take more precautions, but not eliminating tuna completely! It is high in Omega 3s!

-         Air travel – yes, you probably have heard this before, that you are fifty time more likely to be killed in an auto accident than an airline crash

-         Gluten – again the risk is overblown, and avoiding any and all foods that contain it is over-reaction.

-         Vaccine side effects. This risk is now greatly reduced since vaccines are currently produced without the mercury-based thimerosal (especially for children under 6, see the fda.gov site)

-         School shooting, mass  murders – again, the odds are about the same as a small asteroid collision. Yes, it is frightful to learn of the latest on the nightly news, but the job of the news is to evoke fear – so if you want it to abate, cease watching!

-         Zombie attacks or a zombie apocalypse? My virologist friend Beth assures me it will only happen if humans try to revive corpses using cell grafting techniques from live humans – especially by implanting stem cells into cryogenically preserved corpse brains.  Just kidding!

Obama Wants to Give $500m to 'Moderate' Syrian Rebels? Here's A Better Use: Asteroid Detection!

"The dinosaurs could tell you how a serious asteroid hit turns out - except they can't because they're all dead, thanks to a 6-mile asteroid that crashed off the Yucatan peninsula 65 million years ago." - Jeffrey Kluger, 'The Man Who Guards The Planet', TIME, June 9, p. 34.

The recent news that Obama has done an "about face" and decided to ask for money to arm "moderate" Syrian rebels boggles the mind. Here is an intelligent man who merely two days earlier had emphatically told interviewer Nora O'Donnell that such a move - expecting any real results- would be a "fantasy".  As Bill Maher asked last night: How do we even know those to whom we deliver the purchased arms will be the ones for whom they're  intended? Do we have a special 'moderate rebel' detector? Likely not and the arms will simply end up in ISIS' hands just like the American arms dumped by fleeing Iraqi army troops barely 2 weeks ago.

Instead of pissing away $500m on nonsense, I have a better recommendation - one for which planetary astronomers have been screaming. That is, $500m will be the exact amount needed to purchase an infrared telescope to monitor asteroids in space, especially the ones most likely to take us out - like the dinosaurs.

This is not the stuff of science fiction and any human with more than air between the ears ought to have received a wake up call after the Chelyabinsk object struck near that Russian town on the morning of February 15, 2013. The incoming object (small for an asteroid) - ended up injuring 1,600 people and damaging 7,300 buildings. And this wasn't even a direct hit! The object was 66 ft. wide and exploded with the force of 33 Atomic bombs on the scale of the Hiroshima weapon. The only thing that prevented more damage is that the object exploded in the atmosphere (air burst).

To be sure, there's little that we can do to protect against these relatively minor objects. They are simply too small and if they come in from the direction of the Sun,  virtually impossible to pick up before they're literally on top of us. This was the case with the Chelyabinsk object. Currently, NASA's office of Near Earth Objects (NEO) is tracking some 600,000 asteroids but it is a core of 11,000 so-called near Earth objects that garner the most attention. This subset is defined as those asteroids that come within 1.3 AU (1 AU = 93 million miles) . To qualify as what's known as a potentially hazardous asteroid, the object must be at least 460 ft. in diameter and come within 0.05 AU of Earth (or 4.65 million miles). Currently, NASA knows of 1,500 of these objects.

Large asteroids that actually cross the Earth's orbit are the most dangerous, the so-called Apollo objects.  How they emerge as a threat, when their orbits are perturbed, is shown in Fig. 2 above, for Icarus (Fig 1. shows a large asteroid, Gaspra, that - if it struck Earth - would annihilate all life on it)

What makes any large asteroid dangerous, is its mass in combination with its relativity velocity or speed of approach. Thus, large Apollo objects and other asteroids would typically have relative velocities from 11,000 to 30,000 meters per second, or about 6.8 to 19 miles per second. For an asteroid with a 1 kilometer (0.62 mile) diameter, at a density three times that of water, this would generate an equivalent energy on impact of one million Hiroshima sized atomic bombs. Since the Hiroshima explosion was equivalent to 13,000 tons of TNT, this means a larger asteroid would generate an explosive force of 13 thousand megatons. This already is roughly equal to the total equivalent of all U.S. nuclear warheads.
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For a ten kilometer asteroid (roughly 6 miles across) the explosive equivalent would translate into 13 million megatons. This would dwarf all man-made nuclear stocks and warheads, and is rightfully called ‘planet –killer’. It is specifically asteroids of this magnitude that keep asteroid searchers up late at night.

In a recent '60 Minutes' segment on killer asteroids, an appeal was made by two asteroid trackers for a special infrared telescope capable of tracking large asteroids in deep space. The goal would be to identify them and provide a time horizon long enough to be able to deflect them and prevent them from colliding with Earth. (The use of nukes, such as in flicks like "Armageddon", is not fancied by the experts because an imprecise blast could merely reduce one very large object to many smaller ones - turning a bomb into a 'cluster bomb')

Thus, the current thinking leans to long term deflection of large objects - but that requires a lot of time because such deflections amount to tiny fractions of a degree per year. To give an example of one possible method, consider the YORP Effect. This is named after Yarkovsky-O'Keefe-Radzievskii-Paddack – or the trio of physicists that discovered it. It occurs when photons from the Sun are absorbed by a body and re-radiated as heat. In the process, two forces influence the object: one from the impact of the photons, providing a tiny push, and the other as a recoil effect when the object emits the absorbed energy. For small, irregularly shaped objects , YORP can cause measurable changes in motion.

In 2009, I attended a conference sponsored by the Dynamical  Astronomy Division of the American Astronomical Society that featured a paper entitled; ‘Analytic Theory of the YORP Effect for Near –Spherical Objects'. .At that time torques of the form:

dt = r x F dS

 

were considered, where r is the radius vector and F the force supplied. The element of asteroid surface area is dS.  The situations were confined to the cases therefore, where the impinging solar radiation was at right angles to the asteroid’s spin axis.  Three separate detections of the effect were announced, including for  a nearly spherical object (1998 KY), and on two more irregular objects, (1862 Apollo, and 25143 Itokawa).
 

In the case of the Apollo object the observed effect was approximately 3.0 x 10 ^-4 deg/day, vs. the theoretically –predicted YORP effect magnitude of 2.6 x 10 ^-4 deg/day. Earlier, Cornell graduate student Patrick Taylor and assistant professor of astronomy Jean-Luc Margot mapped the shape and located the spin pole of a 100-meter-diameter (about 300 feet) near-Earth asteroid called (54509) 2000 PH5 (abbreviated to PH5) between 2001 and 2005, using radar at the National Science Foundation's (NSF) Arecibo Observatory in Puerto Rico and NASA's Goldstone telescope in California.

 

The results suggest it may be possible to use an artificial YORP effect, generated over time, to deflect a significantly large asteroid. The strategy might include high-powered lasers  mounted on massive spacecraft to deliver one deflecting force.. It may well require using powerful lasers in tandem, say along the lines of a recently -developed high-powered 50kW laser designed by a German firm (http://www.dailymail.co.uk/sciencetech/article-2259639/The-groundbreaking-Star-Wars-laser-shoot-drone-sky-TWO-MILES-away.html

 Combined with other sources of radiant energy directed at the surfaces of the asteroid this could conceivably create an artificial YORP Effect. Then, say in the case of an irregularly shaped object, one might alter its spin axis as well as motion- trajectory, when used in conjunction with the lasers.

 

How long a time horizon might be needed, assuming we can get an infrared telescope in place in an expeditious manner? (And not piss the money away on stupidity). Given that no proper asteroid-deflecting space craft yet exists (we pissed most of the money that could have built one on stupid 'wars' in Iraq and Afghanistan) and it may take five years minimum for its design and construction, we'd like need 10 years. This is according to NEO asteroid tracker Don Yeomans.   Thus, ten years is probably the minimal time needed between the time of discovery of a killer rock that has our name on it, and effecting a deflection that removes the threat.

 

Right now, without even a veneer of protection, things don't look sanguine. Simulations of a killer asteroid impact in 2021 have been conducted by DARPA (Defense Advanced Research Project Agency) and FEMA - using war gaming techniques - and nearly all outcomes disclose we're toast, depending on the exact size of the object. The larger the object the worse the outcome, including worst of all: nuclear winter killing off all crops within 6 months leading to the de facto end of humans. Just like the dinosaurs.

 

The U.S., while it is pressing other nations to get more involved (the U.S. is doing 98 percent of the asteroid tracking) still needs to get its own act together and cease squandering resources on stupid military adventures. Instead, it needs to apply money and resources  to asteroid intercepting and deflecting space craft (and that infrared telescope) instead.

 

On the good side, since the Chelyabinsk object struck, the budget for searching out dangerous asteroids has been doubled to $40m - but this is still a drop in the bucket. If we're serious about not getting creamed into oblivion we will first take that 1/2 billion dollars Obama wants to put toward Syrian rebels to an asteroid detecting telescope instead. Then, we will shut down the Afghan fiasco and put that 1/2 billion to 1 billion toward expediting asteroid deflecting spacecraft design.

 

Our lives may depend on it. While it's true that not all forms of life succumbed when the dinosaur-killing event occurred 65 million years ago, the dominant form was taken out. This is an object lesson we dare not ignore or dismiss given we are the heirs apparent to the dinos' once kingly position. Hence the goal is simple: avoid falling into the same fate.

 

If we are really homo sapiens, as opposed to homo moronicus, we will get on with it!