[J.C. McGILLICUDDY (OP)]

recently it was discovered, due to a impact of a satelite on the moon that there was a significant amount of water in the form of ice ejected outwards due to the impact.in recent shows of yours it was thought that water on the earth came from asteroids that had minute particles of water. It is assumed that the moon was once part of earth before water was on the earth.How is it that the moon could retain any water below its surface. would not with its weaker gravity any water from asteroids, be ejected outside the moons pull of gravity due to the force of the impact? 

[Soul Surfer]

You must remember that the water near the surface was in a crater that never gets sunlight at is base.  The mean temperature of bodies at our distance from the sun is well below freezing. Also the water could be in hydrated rocks.  Finally most meteoric material is in the form of fine dust and dust particles crashing into loose dust would not necessarily get very hot and even then if water wad briefly evaporated it could condense quickly and fall back into the crater.

[yor_on]

Saturn's rings are all made of ice. It seems as as the solar system was created there was a lot of chaotic motion with meteorites, comets etc, shooting in all directions before the planets got their dissonance relative each other ordered and the planets in resonance relative each other. The rhythm of the cosmos sort of, created by the way gravity act upon bodies of mass. So that's where we think water came from (comets mostly, not Saturn:), on Earth, as well as on the Moon (ice).

origin of water.

And Source regions and time scales for delivery of water to Earth (pdf) 2000.