Interstellar Medium Shows It Contains Ammonia, Too

Ammonia molecules have been observed in the interstellar medium by Charles H. Townes, David M. Rank, Albert C. Cheung, William J. Welch and Douglas Thornton of the University of California, Berkeley (Phys. Rev. Letters 21, 1701, 1968). The 1.25‐cm emission probably comes from a dense cloud of 3‐minute angular diameter in which strong OH absorption had previously been reported, according to the Berkeley group.