My husband and I watch the sky at night. Many times we have seen flashes of light high in the sky. Usually there is only one flash, but sometimes two and rarely three. Our thoughts are that this could a be strobe light on some kind of high flying aircraft, but there are no red and green lights, and no lights of any other kind--just the bright flash. We see this fairly often. This is not a meteor. It is not a satellite. We have seen meteors and satellites for many years, and we see planes flying over all the time. This is something much different. It usually only strobes once and then the light is gone forever, so it isn't an ordinary airplane. Very rarely (hardly ever) it flashes twice. Could it be some sort of military operation? We are near two air bases--50 miles from one and 35 miles from the other. Whatever this thing is, it isn't displaying any other lights. Could you please tell me what these lights are? Thank you.