I was traveling with my Wife on RT 378 South from Bethlehem in to Lower Saucon, When we got to the top of 378 & Mountain Drive, We observed a very bright Low Flying Fireball. It crossed 378S & Mountain Drive, flying above some houses, maybe about 200 Ft off the ground. We continued down 378 and made a left on to Seidersville Rd. Seidersville road runs parallel to mountain drive. We observed the Fireball still flying over the housed to the left. It gained altitude and disappeared in to the sky by the time we got to Hickory Hill Rd - Bridge. It made no noise and was a red/orange pulsing color.