  We analyze findings of the Stardust mission that brought to the Earth dust
from the 81P/Wild 2 coma. Just as the data of the Deep Impact mission to
9P/Tempel 1, they are at odds with the widely accepted condensation/sublimation
comet paradigm. They fit rather well to the approach assuming ejection of
nuclei of short-period comets from moon-like bodies of the type of Galilean
satellites in rare (six to seven events in 4.5 aeons) global explosions of
their massive icy envelopes saturated by 2H2+O2, products of the electrolysis
of ice. This approach offers an explanation, in particular, for the jet
activity of comets, which is sustained by combustion of the 2H2+O2+organics
mixture ignited and complemented by the solar radiation. Combustion accounts
also for other observations, in particular, the presence in the dust of
products of high-temperature (800-900 K) metamorphism. The presence of minerals
forming at still higher temperatures (~1400-2000 K), just as the undoubtedly
planetary origin of some long-period comets arriving from the joint
planeto-cometary cloud beyond Neptune, forces one, however, to invoke the
close-binary cosmogony of the Solar system, which three decades ago predicted
the existence of such a cloud (in the recent decade, this prediction has been
substantiated by the discovery there of many dwarf planets). It considers the
Jupiter-Sun system as the limiting case of a binary star and uses it as a basis
for explanation of all the known observations and for prediction of the new
ones to come. It provides an explanation, in particular, for both the origin
and capture by the Earth of the Moon as a high-temperature condensate and the
formation of the Galilean satellites, which also contain inclusions of
refractory minerals in their ices.
