a possible impact factor


In my last post related to the climate change and the G8 summit the possible uses of nuclear energy were mentioned. Among others it was remarked that nuclear material in particular uranium should not be used up in dangerous commercial nuclear power plants (where I havent even mentioned the use of these for weapon production) but e.g. rather be kept for space travel (here a rather futuristic proposal?). Here yet another suggestion:

It is a common knowledge that an outer enemy may enforce social cohesion within a social group. If this social group would be the humans on earth then there is a rather realistic outer enemy, which provides at the same time another useful use for nuclear energy, namely:

meteroids or asteroids’ impact events

According to wikipedia the late Eugene Shoemaker of the U.S. Geological Survey came up with an estimate of the rate of Earth impacts, and suggested that an event about the size of the nuclear weapon that destroyed Hiroshima occurs about once a year. Such events would seem to be spectacularly obvious, but they generally go unnoticed for a number of reasons: the majority of the Earth’s surface is covered by water; a good portion of the land surface is uninhabited; and the explosions generally occur at relatively high altitude, resulting in a huge flash and thunderclap but no real damage, however clearly bigger meteroids may come up. According to Nick Bostrom section 4.10:

In order to cause the extinction of human life, the impacting body would probably have to be greater than 1 km in diameter (and probably 3 – 10 km)….It is estimated that a 1 km or greater body collides with Earth about once every 0.5 million years.

So in order to get a feeling for the probabilities:, the probability that this is going to happen in a year is about 28 times more then a lottery win in a lottery 6from49

So it is not that unlikely as many people think! May be it is useful to raise awareness for this danger.

For that reason e.g. the NASA published a study, which deals with this threat called
SHIELD—A Comprehensive Earth Protection System. I cite from this article:

For large hazards or short lead times, nuclear detonations are the only possible mitigation option in the near future. In terms of sheer efficiency, a nuclear detonation will provide the most ∆V for the least amount of weight of any system proposed here, given reasonably short mission times. No other device currently proposed can release the kind of energy per mass that a nuclear device can.


The non-nuclear technologies discussed provide an array of options for smaller bodies. Propulsive technologies such as chemical, electric, solar sails, directed energy, and mass drivers would only be effective against smaller bodies. For larger bodies the amount of fuel needed would become too large to launch into orbit.
By far the biggest disadvantage to nuclear detonations is the political and social ramifications of developing such a large, accurately targetable, highly reliable nuclear weapon. This might infringe on several treaties, and a launch
failure could cause extreme amounts of destruction. However, because of the current state of technology, not a lot of modifications would be needed to upgrade current weapons from their military role to one of hazard mitigation.

->funny Earth Impact Effects Program
for europe see also ->europaeisches feuerkugelnetz (english?)


4 Responses to “a possible impact factor”

  1. Quintin Skov Says:

    Thank you in behalf of sharing this acquaintanceship!

  2. Victor Says:

    link to DLR is interesting. They write:

    As a result, there exists a population of “near-Earth asteroids” (NEAs), which poses a small but real hazard to civilization.


    Can we protect our civilization from the next major impact? Various initiatives are being taken by space agencies, including ESA and NASA, and research groups around the world to identify potential future impactors, investigate their physical characteristics, and develop strategies to mitigate against impacts. The DLR Department of Asteroids and Comets contributes to this effort with a number of programs:

    Contributions to the design, development and execution of relevant space missions, such as Rosetta, Dawn, AsteroidFinder, Don Quijote, ASTEX.
    Observations of near-Earth asteroids with space-based and ground-based telescopes, such as the Spitzer Space Telescope, NASA Infrared Telescope Facility, with the goal of characterizing their physical properties.
    The maintenance of a database of near-Earth asteroid physical properties, such as size, shape, rotation state, taxonomic class, etc. (EARN).
    The development of models, e.g. thermal models, of asteroids and comets to facilitate the interpretation of observational data.
    Studies and modeling of the effects of impacts on the Earth.


    An on-line data-base of Physical properties NEOs, with the corresponding bibliographical references is available for each individual NEA. This data-base, compiled and maintained at DLR by Gerhard Hahn, contains information on all known near-Earth objects (Atens-Apollo-Amor Asteroids), and is updated on a regular basis.

    So there is someone having an eye on these objects!

  3. nad Says:

    Victor wrote:”So there is someone having an eye on these objects!”

    Yes and for a centralized european coordination:

    Watching for hazards: ESA opens asteroids centre

    ESA today inaugurated a new hub that will strengthen Europe’s contribution to the global hunt for asteroids and other hazardous natural objects that may strike Earth. …..
    The NEO Coordination Centre will serve as the central access point to a network of European NEO data sources and information providers being established under ESA’s Space Situational Awareness (SSA) Programme.


    ESA’s NEO Coordination Centre (NEO-CC) is operated by Space Dynamics Services S.r.l. (SpaceDys) under a contract with Elecnor Deimos, Spain, on behalf of the Agency’s SSA Programme Office.

  4. a Visitor Says:

    then there is a rather realistic outer enemy

    So do you think aliens are no threat?

    Have you seen this report in the New York Times about this telescope scanning for extraterrestial life (via boing boing)?

Leave a Reply

The below box is for leaving comments. Interesting comments in german, french and russian will eventually be translated into english. If you write a comment you consent to our data protection practices as specified here. If your comment text is not too rude and if your URL is not clearly SPAM then both will be published after moderation. Your email adress will not be published. Moderation is done by hand and might take up to a couple of days.
you can use LaTeX in your math comments, by using the [latex] shortcode:
[latex] E = m c^2 [/latex]