I saw a Sphere like object, silver in color floating in the sky before it just disappeared

I was driving home from work(security officer at an airport) around 8am when I saw a single silver looking object out of my right window, it wasn't really moving at all, more like hovering in the sky and when I rolled down my window to see if I could hear the sound a helicopter makes(originally thought it was a helicopter)I heard no sounds at all besides cars on the freeway, i kept watching it for about 30 to 40 seconds and then it just disappeared. About 6 to 8 months ago I saw almost the same silver object in apple valley CA, but it was closer and looked more the shape of a blimpie but it was also silver in color, barely moved, made no sound and disappeared within 60 seconds. On both occasions I was driving and it was a clear and sunny day with no clouds. I've never seen anything else like it before. There was no other aircraft in the area that I could see or hear other than this object.