I was just watching t.V. in my home, my window open. i then heard a loud hum and loud jet engine from inside the house, went outside to investigate and saw an aircraft, very dimly lit with blue lights possibly 8-10 lights in a row from my view, and if i were to guess the overall shape i would have to say cigar even though the craft was very dark and almost impossible to see on the dark sky background. it was flying approximately 400 mph, with a jet plane following directly behind it approximately 100 ft. they were flying on a very straight path. i watched them both until out of sight, the path was from joshua tree, ca, toward the west of palm springs area then out of sight. i distinctly heard a very loud constant hum which first struck me ass very odd as i have heard aircraft and helicopters before fly in this area. this hum noise was very noticeable as being very different and not a typical aircraft which is why i went outside to see what it could be. the jet following the u.F.O. seemed as if it was there to mask the noise of the hum. the whole even only lasted for 4 min. from my perspective, and i did not have time to grab a camera, but the dim light of the u.F.O. would not have been visible on camera anyway.