Large white sphere observed East of Yuma for about 50 minutes. Disapeared when military craft aproached.January first, 2003. Driving on rout 8 from West to East, having passed Yuma about 15 to 20 miles behind, we noticed a bright white ovoid object to the North, above the mountain range. I mentioned the fact to my family; my wife and two teenage daughters, and we started to speculate what it could be. We quickly discarded that the object could be a plane, blimp, weather balloon or cloud. What was odd was the apparent size of the object and the fact that it was stationary, floating or hovering in the sky. I stopped on several occasions during the next half hour to photograph the object. Traveling at an average of 80 miles an hour, we were able to see the object for over 50 miles, and still distinguish it clearly. The shape looked a little different from this latter angle, a shade appeared in the middle of the object that looked more cigar shaped than previous. We thought that it could be two ovoid shapes together or a peanut shaped object (see photos). At approximately 10:10 AM two military craft were coming in from East to west over the highway. I assumed that they were military because of the fact that they were leaving vapor trails, and were flying side by side, a formation civilian planes do not oftenly practice. At seeing these planes, I asked my girls to see what the UFO would do and they mentioned that it had disappeared. Because the mountain range was low in comparison to the height of the object, the fact that we were on a straight away, and the fact that we had observed the object moments before, we concluded that in fact it did disappear and was not obscured by the scenery.