  We prove existence of all moments of the multiplicative coalescent at all
times. We obtain as byproducts a number of related results which could be of
general interest. In particular, we show the finiteness of the second moment of
the $l^2$ norm for any extremal eternal version of multiplicative coalescent.
Our techniques are in part inspired by percolation, and in part are based on
tools from stochastic analysis, notably the semi-martingale and the excursion
theory.
