I noticed a very strange airplane flying low to the ground. It would circle and then hover, circle and then hover.My husband and I were driving to Lubbock, TX. I had been asleep. When I woke, I noticed a very strange airplane flying low to the ground. It would circle and then hover, circle and then hover. It wasn't a helicopter though; it was a long aircraft with wings far back on the tail. I said to my husband, "What is that weird plane?" He said that he didn't know, but he'd been watching it for sometime. He told me to watch because it would seemingly stop right in mid-air--which is what I had observed it doing. It seemed to be circling the highway, but keeping up with the traffic that was north-bound. It was a clear day; few clouds. No rain. Other motorists appeared to be watching the craft was well. It eventually took off very rapidly southward and disappeared. Our background--husband is a professor; I am a writer. This is the first sighting for my husband. My 2nd-- the previous happened 35 years ago. We think it may have been some kind of test plane for the gov't. Lubbock Tx occasionally experiences tremendous sonic booms. The testing may have come from Reese Airforce Base at one time,. but it's closed now. I don't know where this craft would have orginated from.