Forming Binary Near-Earth Asteroids From Tidal Disruptions

Figure 4.3: Comparison of this work, using HNBODY to calculate binary disruption probability(solid line), with results presented in (Bottke & Melosh 1996a, squares).counter distance is determined for each binary semi-major axis as the distance at which50% of randomly oriented binaries disrupt due to the tidal forces of the close encounter.The statistical encounter probabilities for each critical distance then determine lifetimebetween binary-disrupting encounters (Table 4.1). The lifetime for very close binariesof 4 or 6 R pri is only 2 or 1.6 Myr, suggesting that many of the observed NEA binariesare potentially quite young. The NEA binary Hermes has a semi-major axis of 5 R pri ,91