Bright round slow moving light with spotlight and colorful tail, explodes.Five of us were coming back from a bike ride on Hwy.89 near Truckee, Calif. Round large light moving slowly with a cone shaped tail of blue, purple light, sparker type behind it. There was what appeared to be a spot light from it. The object moving upward. Very bright and then it exploded and a bright light was left including the tailings of color. Moon to the left so the light of the object was not from the moon. Didn't hear any noise of explosion or see any debri. Others driving, stopped to witness it. I thought it was an aircraft of sorts. Was told by the Highway Patrol, that it was possibly from Landenburg Launch.((NUFORC Note: Missile launch from Vandenberg AFB at 1936 hrs. on 14OC02. PD))