My husband and i witnessed 2 objects that looked star-like become very bright for a few moments before dimming again in the northern sky. we witnessed this for 2 hours as they stayed in the same general area. they would dim out whenever airplanes were in the area. they had no sound and left no trail. one emitted a blue/white light while the other was more red in color. they hovered and changed directions very quickly before coming to an abrupt halt. one became as bright as the moon before fading in brightness again. they also would quickly flash their light before (turning them off). we first noticed the objects while riding in the car on our way home. when we got home we walked to our lake in the backyard to get a better looked at the sky. again we could see the objects. the brightness from one of the objects is what caught our attention. we don't know what they are but we know they are not airplanes or helicopters. o were very curious about the incident. i had a similar incident happen a few nights ago also in the northern sky except that incident they stayed lite up for long periods of time and only dimmed out when airplanes approached. they moved quickly in all directions; something i know an airplane can not do. the lights were continus until dimmed but never blinking. we tried to take a video but our cameras could not pick up the lights. the objects eventually moved out of sight below the horizon on both occasions.