This magnificent Electric Universe documentary, demolishes the gravity, mass, dirty snowball, comet theory.
You-tube commentators ask- "So what is all that waffle, dished up, on the Discovery channel ?"
After the comet was struck by a high velocity, 300 kilogram, copper projectile, a NASA spokesman says, the man-made, almost non-existent impact crater, "must have filled itself up again" And we are all laughing out loud.
And the comet water trail is formed by hydroxyl ions, from electrically excavated rock, combining with solar wind particles.