Bright white fast-flying UFOI was taking final photos of a 60m meteorological measurement tower that we had just installed northwest of Clayton, NM, and noticed this object flying overhead at a good altitude in a northwesterly direction and as fast as a normal passenger jet.I could hear a sound like an airplane and assumed that the object I was seeing was just a jet, but then noticed that it really didn't look like a normal jet and left no contrail. By the time I decided to get it on camera it was far away but I zoomed in to take a couple of pics.It could be some kind of experimental aircraft or zeppelin, I don't know, I never could see a clear shape to it.I will send the photos by email, they were taken with a GPS camera so you can see in the properties the exact coordinates where the photo was taken. The time in my camera is wrong. Earlier in the same day I had noticed a very odd small bright white saucer-shaped cloud hovering to the west that didn't match anything else in the sky and had pointed it out to my co-workers, joking that it was a cloaked UFO, but not sure if there is any connection or not. I don't think any of them noticed the one that I snapped pics of, as they were already in trucks leaving the site. I will ask them when I get a chance.