My adult daughter and i were traveling west on us why 78 when she noticed a very bright light that appeared to be traveling from the south-east toward north west. just as she made reference to the tremendous speed of the object, it just disappeared. we continued to look to see if it reappeared but it did not. the sky was completely clear with no clouds visible at all. there area where the light was observed was not obstructed by trees, structures or other obstacles that might block the view of the object. we live within 50-60 miles of atlanta's hartsfield international airport and are very familiar with the normal air traffic, aircraft marker lights, strobes, etc. this object was a goldfish yellow light, constant brightness with no blinking lights on or adjacent to it. we are certain that it was not a meteor or "shooting star". there was no trail or "tail" behind the object. it appeared to be traveling about twice as fast as a normal aircraft during the time it was visible.