Silent object near house at low altitude and considerable speed with lights.Sitting at my desk I noticed outside my window to the north what I thought was a helicopter about 500 feet off the ground moving from west to east. Then it occurred that this object was moving to fast to be a helicopter so I jumped up and opened the window thinking I would hear engine noise. However, to my surprise, the object was not making any sound. The object had one white light, one blue light and two red lights, one of which was flashing. My son got up to view the object, but it was gone by the time he got to the window. I would think that this object was moving approximately 500 to 600 knots.((NUFORC Note: We spoke via telephone with this individual, and we suspect that the report is quite accurate. PD))