Very bright red light, moving slowly east to west then went straight up and disappeared.Observer: Retired commercial pilot with over 45 years of flying experience.((ADDENDUM FROM WITNESS))Peter:My house is in a cul de sac and faces 060 degrees. Traffic into Midway all day and evening were using 4R approach, which I am about 500ft to the right of center line. The object appeared to be about 3 time the size of Venus, only red. Altitude is difficult to determine at night, but I would say not more than 5000 agl, as that is what I'm estimating from observing the aircraft and personal experience flying into Midway in this area.I was also the director of Flight Standards for ((deleted--aviation entity)) and Chief Check Pilot for ((deleted)) yrs in addition to my 40 some years of flying in the Chicago area.The object appeared to be heading 270 degrees from our perspective, (right to left). My wife and grandson also observed the object. No aircraft are vectored into Midway from that direction (to tight of a turn on to the localizer).It was no aircraft, as when I first saw it I ruled out Mars, as it was too low in the sky and much brighter. Then I did look for position lights, and saw none. It was at that time I called my wife outside, as I our grandson was already outside with me. We then observed it for about another 3 minutes when it got to approximately 10 degrees to the right of our house, it went straight up and disappeared. Distance from out house approximately 1-2 miles. Drivers eastbound on I-80 and northbound on I-55 would have seen it also.It was awsome. Glad we were able to observe it.Hope this helps((END ADDENDUM))