The Hundredth Monkey Phenomenon

Centauri Dreams describes an interesting solution in a recent paper by Didier Massonnet and Benoît Meyssignac (Centre National d’Etudes Spatiales, France) to the very real possibility that our beloved Earth will be pummeled by some large, hard, ridiculously fast object at some point before the sun goes nova, some 4 billion years from now. The basic idea is to use a small asteroid that has been captured and is circling the Earth like a second moon to deflect any larger object.

We…have a detection challenge: we seek an asteroid small enough to be manoeuvred “easily”—i.e. within a 10-year time frame and with a typical ΔV which we set at 50 m/s—while large enough to ensure the destruction or the deviation of Goliath. David must be energetically close to the Earth, which means that its initial semi major axis is close to one astronomical unit and its eccentricity as well as its inclination are small. David may be too small to be easily detected by optical means, in addition of being often in the angular vicinity of the Sun. The best way to detect efficiently such an asteroid might be by radar survey.

Check out the post for more info.