I went outside my house to get some fresh air and look at the stars at approximately 10:05pm. I looked up and saw a bright sphere-like object, initially thinking it was a star as it had a twinkly sort of light at first. I noticed it began to move across the sky. I watched it to make sure it was moving and then asked my friend to come outside and take a look at it. We both saw it moving from the southwest to the northwest in a straight line. As it did this, the entire object seemed to dim and brighten, but not a patterned or organized way. It did not seem to have a "rhythm" to its dimming and brightening. It flew out of view within minutes. Standing out there after the object was gone minutes later, I saw two separate planes flying in different directions. The planes' blinking and flashing lights contrasted starkly with the glowing and dimming of the other object that I saw that night.