a point of light appeared, moved from N to S, stopped. from stopping point to west, back to stopping pt., then to east. back to s.p., then back the way it came

it was a clear night.  i had just come from dropping off a friend.  leaving the car at home, i walked down to the beach.(sebago lake, in s.w. maine)  sitting on the beach, looking up at the sky, i saw what appeared to look like a point of light, star-like. no details visible, and no sound. sitting on the beach, i was facing the water, looking NE.  this point of light appeared, and, in a straight line, came from n.e. to s.w. it stopped, made a 90 degree turn to the n.w., returned to the stopping point, hesitated, and sped to the s.e.  returned to the stopping point, again, and sped away, faster, towards the n.e., going back the way it had come. this all happened in about 6-10 seconds. not sure of the exact date, as it was over 20 years ago. i was in college, although not at the time of the incident, during the summer.