RE: Large Triangular object just outside Boston

I am writing this in response to the Allston, MA UFO sighting on the same date. I cant confirm this is the exact date of my sighting. I had an inclination to see if anyone else saw what I saw in approximately the same time period. I surfed through the listings on this sight and was surprised to find a listing during the approximate time i was looking for. The description of the event was exactly the same as what i saw. I was coming home from a sports practice. I was about ten years old. There were three other people in the car including my mom. The practice was in acton and we saw the craft about ten minutes into the trip home to chelmsford. All of us joked about it being a ufo cause the trip took a by a small airport along the high way. It wasnt until we saw the craft moving in untraditional ways to a normal aircraft that we were a little taken back. The craft moved extremely fast and agile. It would pick up speeds that i had never seen in a normal aircraft and then instantly turn around the other direction... as if it didnt have to slow down to turn around. I realize helicopters have this capability basically, but there was no noise, and the speed and liquidness that the turn around was, could not have been a helicopter. This craft remained in view for at least a half hour all the way back to chelmsford center where we lost view of it. One specific thing about the craft is we could vaguely make out a trianular shape about it. Chelmsford is about 30 minutes north of boston.