Asteroid Impacts and the Press

by Paul Gilster on July 28, 2007

In a world where climate change is everywhere under discussion, its causes pondered and its effects debated as political fodder, I suppose it makes sense that The Economist would look at the danger posed by Earth-crossing asteroids in the same context. Thus the sub-title of its recent story on the subject: “The ultimate environmental catastrophe.” Which, of course, an asteroid impact could well be, particularly if large enough or placed in a highly populated area.

I’ve subscribed to The Economist off and on for decades, always admiring its clarity and style. The magazine handles this subject with skill, noting how quickly the living ecology of Earth scrubs away the tell-tale signs of impact craters, citing the Moon as a counter-example, and going on to note that the Earth Impact Database in Canada can nonetheless identify more than 170 such craters. And it reminds us of NASA’s scientist David Morrison’s statement that a large meteorite strike is the only known natural disaster that could put civilization itself at risk.

How the press presents complicated stories to the public has consequences on the terms of subsequent debate. The current article runs through the options for changing the orbit of dangerous objects, ranging from nuclear weapons to nearby spacecraft using their tiny gravitational effects to move the asteroid gradually off course. Worthy of greater emphasis, in my opinion, is the amount of time the latter (more practical) method would need to accomplish its work. Whatever the method, we have to pick the danger up early, allowing ourselves an adequate window to muster the resources needed.

We also have to have the infrastructure in space to do what needs to be done, whatever course we choose. Instead, we are closing down options here on Earth. The Arecibo radar installation is under immediate threat of de-funding, a potentially devastating loss to our ability to find and catalog Earth-crossing objects. Meanwhile, other than the all too occasional story, the media focus instead on useful scandals that draw viewers and readers. Lisa Nowak and her tortured love affairs. Drunken astronauts being rocketed into space. All are certain to drive ratings up.

As to the latter, I’ll just say this. If I were about to board a craft that would muscle me into orbit using two solid-state boosters, neither of which could be throttled back or shut-down once lit, I would demand more than a single drink before I walked to the launch gantry. And as for the press, let’s hope for more articles that remind the public of the stakes involved in asteroid collision. We may or may not have time to avoid another Tunguska, but the need for a flexible space-based response to the danger should be kept front and center. We don’t need alarmism, but we do need a thoughtful, prepared public that understands the issues.


Gregory Benford July 28, 2007 at 16:38

Amen! The slow gravitational tug requires long, many-year operations, highly unlikely. Having nuclear fusion warheads on dedicated launch vehicles is much cheaper and more practical. We should try a real experiment, too, far from Earth, after much simulations R&D. I looked at this problem in detail in the 1970s, even wrote a novel about it (SHIVA DESCENDING), and alas, nothing has much changed. The Arecibo shutdown is a symbol of how little this short-attention-span society does.

Ron S July 28, 2007 at 19:14

Great idea but it would take quite an effort. By effort I mean political and public relations, not technical. Remember the brouhaha over Cassini’s RTG? Try it with a real warhead. I seriously doubt that NASA, the Russians or even the Chinese would dream of taking this step just because of the likelihood of an international uproar let alone the public outcry. I don’t see this happening anytime soon. Unfortunately.

MaDeR July 28, 2007 at 19:44

“The slow gravitational tug requires long, many-year operations, highly unlikely. ”
What? We in ANY case will need many, many years. If tomorrow we discover nice chunk of rock that will hit Earth in one year, we can only pray.

“Having nuclear fusion warheads on dedicated launch vehicles is much cheaper and more practical.”
And infinitiley more dangerous. Especially if asteroid after blast fragments and hits oh-so-many places of Earth, doing equivalent of carpet bombing with thermonuclear warheads. Howww nice. You watch dumb pseudo-SF movies too much.

“Remember the brouhaha over Cassini’s RTG?”
Comparring RTG with nuclear warheads in space is… well. Telling you my opinion about your inteligence would be ad hominem (with very bad words), but you can imagine what I think.

“taking this step just because of the likelihood of an international uproar let alone the public outcry.”
Reason for that would be somewhat different than protests against RTGs in Cassini. Nothe that protests agianst latter was NOT “international uproar” or “public outcry”.

“I don’t see this happening anytime soon.”
Hitting asteroids with nuclear warheads? Hopefully never.

philw July 29, 2007 at 15:27

Sad to see unscientific anti-nuke hysteria here. There’s a time and place for a variety of roid deflecting techniques including gravity tug, mass driver, nukes and other techniques not yet imagined. Nuking a roid does NOT cause ‘carpet bombing of Earth with thermonuclear warheads.’ Perhaps I’m reacting to hyperbole.

Enjoyed ‘Shiva Descending’ immensely, as well as other works. One astronaut character in Shiva reminds me of NASA’s girls gone wild astro. :)

ljk July 30, 2007 at 12:07

Asteroid Deflection: How, where and when?

Authors: D. Fargion

(Submitted on 12 May 2007 (v1), last revised 27 Jul 2007 (this version, v2))

Abstract: To deflect impact-trajectory of massive km^3 and spinning asteroid by a few terrestrial radiuses one need a large momentum exchange. The dragging of huge spinning bodies in space by external engine seems difficult or impossible. Our solution is based on the landing of multi screw-rockets, powered by mini-nuclear engines, on the body, that dig a small fraction of the soil surface, to use as an exhaust propeller, ejecting it vertically in phase among themselves. Such a mass ejection increases the momentum exchange, their number redundancy guarantees the stability of the system. The slow landing (below 40 cm s^-1) of each engine-unity at those lowest gravity field, may be achieved by save rolling and bouncing along the surface. The engine array tuned activity, overcomes the asteroid angular velocity. Coherent turning of the jet heads increases the deflection efficiency. A procession along its surface may compensate at best the asteroid spin. A small skin-mass (about 2 10^4 tons) may be ejected by mini nuclear engines. Such prototypes may also build first save galleries for humans on the Moon. Conclusive deflecting tests might be performed on remote asteroids.

The incoming asteroid 99942 Apophis (just 2% of km^3) may be deflected safely a few Earth radiuses. Its encounter maybe not just a hazard but an opportunity, learning how to land, dig, build and also to nest save human station inside. Asteroids amplified deflections by gravity swing maybe driven into longest planetary journeys.

Comments: 14 pages, 5 figures

Subjects: Astrophysics (astro-ph); Space Physics (

Cite as: arXiv:0705.1805v2 [astro-ph]

Submission history

From: Daniele Fargion [view email]

[v1] Sat, 12 May 2007 23:50:03 GMT (353kb)

[v2] Fri, 27 Jul 2007 11:39:36 GMT (380kb)

Steve Pease July 30, 2007 at 14:08

I especially like the suggestion in the abstract above that Apophis represents an opportunity to test diversion concepts. Are any space missions under consideration? By B612 or ??

Steve Pease July 30, 2007 at 14:16

There’s a nice story currently on about a manned mission to a NEO – tangentially relevant to this topic.

ljk July 30, 2007 at 15:45

NASA Insiders Propose Stepping Stone Path to Deep Space

By Leonard David

Special Correspondent,

posted: 30 July 2007

01:07 pm ET

Full article here:

To quote:

Internal looks by a small group of NASA “NEOphytes” have projected that a human trek to one of those mini-worlds may involve two or three astronauts on a 90 to 120-day spaceflight, including a week or two week stay at the appointed asteroid.

Dispatching astronauts to a NEO is a sensible idea, said Harrison Schmitt, Apollo 17 astronaut, geologist and current chair of the NASA Advisory Council (NAC).

In fact, the Exploration and Space Operations subcommittees of the NAC were briefed July 18 by NEO study team members from the NASA Johnson Space Center, although there has been no Council action on the topic.

Schmitt told “I think examination of a NEO mission and the development of the stand-by monitoring systems, plans, protocols and procedures for the diversion of a potentially Earth-impacting asteroid would be very prudent activity for the U.S. to undertake.”

Additionally, Schmitt said that a NEO mission would be a potentially important demonstration of the versatility and capability of the Constellation systems and a “gap-filler” before any Mars landing mission.

“So far, the arguments for asteroid science and resources are interesting, but not well-developed or potentially as historically or politically persuasive as a demonstration of long-term Earth defense,” Schmitt said.

ljk July 30, 2007 at 16:23

Great digitalspace page going into detail – and a lot more images -
of the proposed manned NEO mission:

philw July 30, 2007 at 20:58

In my view we would gain so much more science, develop practical planet saving techniques and have wicked pissah fun by using the proposed post-Apollo spacecraft for NEO missions rather than a return to the moon, exception being unexpected discovery of ACCESSABLE water at the lunar poles.

ljk August 7, 2007 at 10:11

NASA plans ‘Armageddon’ spacecraft to blast asteroid

Flight August 3, 2007


NASA’s Marshall Space Flight Center
has designed a
nuclear-warhead-carrying spacecraft
to deflect an asteroid that could
threaten all life on…

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