Witness was a passenger in a car driving home from the grocery store when she and her friend observed an aircraft of some kind. she assumed it was one of ours like a satellite plane. they then noticed that it was chasing a white globe of light in the sky approximately 200 feet in front of it. the light was heading from east to west and was within 500 feet of the witness. the light was observed for approximately 10 seconds before disappearing behind a building. the aircraft chasing it had blue and red lights on it, and possibly white. five to eight seconds later the witness turned and observed what she believes was a helicopter coming from behind her and following a cylinder shaped object with approximately six blue lights in a straight line on it. these objects were traveling north to south.