In the afternoon of may 25th, i observed a nearly stationary, black spherical object from my home balcony. the balcony faces south towards downtown chicago, which is only about 1 mile away. the object appeared to be over the south loop area or just to the west of highway 90. i observed the object for about 10 minutes before it appeared to fade away without moving. i have included a video i shot from my iphone as the object can be referenced just to the west of the willis tower. with my iphone i could zoom into the video and observe the object spinning/pulsing.