Sphere with clear halo seen in Mexico CityMexico City. December 21th 2008. 11:30 am Local time.My mother and I went up to the roof to take some warm from the sun. The sky is cloudless and very bright. Looking up to the west we both saw a very brilliant sphere sorrounded by a clear halo. It was moving west to south with uniform speed. While travelling, it seemed to be spinning on its own axis, because we could see it shinning for a moment, and then the shine went very opaque, almost invisible against the sky, then again, this shine came back. Seemed like it was partially reflective and partially opaque.At some some point, it crossed just below of the morning moon and and aircraft passed at the same time. It continued moving towards the sun and it became very difficult to see because we had the sun in front of our face.I guess the clear halo was 2 or 3 times the size of the sphere.