In 1967, a Soviet astronomer called for a "joint effort of all the scientists of the world" to determine the nature of unidentified flying objects. The scientist, Feliks Zigel, was so convinced of the existence of flying saucers that he said, "Unfortunately, certain scientists both in the Soviet Union and in the United States deny the very existence of the problem instead of helping to solve it." His concern was prompted by some 200 reported sightings of "a luminous orange-colored crescent" whose "surface is only a little duller than that of the moon." It was also said to "throw out jets, sometimes with sparks." Such suspicions eventually gave rise to a study commissioned by the Soviet authorities in 1978 to research paranormal phenomena. The resulting documents allegedly make clear the seriousness with which the Soviet government treated the prospect of an alien invasion.