Eastern Colorado lights.Myself and one other witness observed a single light in the sky, which grew brighter over a period of about 5 seconds before it expanded into multiple lights composing a straight line of individual lights. Said lights then reformed a single ball of bright light before fading out. This then repeated 4 separate times in different locations in the sky before stopping. No sounds accompanied the lights and no sounds followed. Appearance very similar to military aircraft defence flares to begin with but vastly different in behavior after initial flash.