January 10, 1950
10:10 AM. A man and his father were observing two  (2) F-80 jet fightar aircraft coming in for a landing  approximately eight miles from Las Vegas Air Force Base at an angle of approximately 45 degrees into the sun and saw an object at an altitude of approximately 1500-2000 feet. They stated that the object was within their vision for approximately twenty five (25)  seconds, and that the appearance of the object was pure silver, round "like a balloon" and apparently constructed of. a solid material, "a metal". They stated that the object was approximately 25 or 30' in diameter and that the direction of flight was Northeast by North,  and that they observed no tactical movement, or maneuver of the object, but that had it been an airplane, it could have been observing the flight of the jet aircraft. They also stated that the motion of the object was smooth; at first slow and then a very rapid acceleration in a horizontal ascent,  disappearing over mountains to the east.

http://www.bluebookarchive.org/page.aspx?PageCode=NARA-PBB91-862

NARA-PBB91-862-863