Yellow/white ball of light.I walked off my porch looked South and observed a yellow/white light the size of Venus, about 15 degrees above horizon. Being an amateur astronomer, I knew there should be no yellow lights near that position in the night sky.I was about to go get my binoculars, when the light moved due West about two miles in an instant. I observed it as a bar of white light as it moved.It then sat motionless for about 20 seconds. Then it went straight up and out of sight in an instant. Displaying the same bar of light that it had during its horizontal movement.I then went and got my binoculars and observed nothing in the position I last saw the light. Made no noise at all. Sky was moonless and winds calm about 32 degrees F. I am a member of MUFON.((NUFORC Note: We spoke via telephone with the witness, and he seemed to us to be a serious-minded person. We suspect that he is an excellent observer, and witness. PD))