Standing in the backyard I just happened to look up. I believe I looked up because of the heavy airplane traffic that we've been experiencing over the house due to runway changes at O'Hare Airport lately. I noticed on the East horizon a solid yet fuzzy object flying VERY fast Westerly. The object was very high up (Satellite height) but still appeared about the size of a basketball. I immediately pointed it out to my roommate who witnessed the entire event with me.The object looked sort of like an egg in a frying pan, yellowish oval with a dark center spot. It flew from horizon to horizon in approximately 1 to 2 minutes. As it approached the West horizon, it started to zig zag sharply while still heading in the same direction and then paused briefly, then continued in a straight flight pattern. It looked as if it flew past the Earth, not orbiting the Earth. About 30 seconds later, an exact duplicate flew over but was a bit smaller, looking like it had more altitude. The second object flew straight, from and to the same direction, but this one did not pause or hesitate. They both were flying at a very fast rate of speed, as I have seen satellites orbiting the earth when doing night fishing on Minnesota lakes, these were definitely NOT satellites, or high flying aircraft.Neither one of us had or have ANY idea what these objects were. I've never seen anything like this in the sky before. I was very excited to finally witness what I've only heard about through MUFON and its TV shows. After 50 years of looking toward the sky... this was simply an amazing sight!!