The size, mass, mass loss and age of Halley's comet

Halley's comet (1910 II, 1982i) has a D²p_υ value of 5.90±0.33 km², where D km is the diameter of the nucleus and p_υ is the geometric albedo. The mass of the nucleus is $$7.5\times10^{15}\enspace \varrho p_\upsilon^{-1.5}\enspace \text g$$, where ϱ is the density. Reasonable assumptions as to p_υ and ϱ yield diameter and mass values of 9.4 km and 2.2×10¹⁷ g. In the 1910 apparition the comet lost a mass of 2.8×10¹⁴ g which is equivalent to an absolute magnitude change of 9×10⁻⁴ per apparition. The mass of the meteor stream, produced by the decay of P/Halley, is consistent with the statement that the comet has had 2300 previous close passages of the Sun. The comet will probably disappear altogether alter another 2300 close perihelion passages.