Apollo 11 was the spaceflight that landed the first humans on the Moon, Americans Neil Armstrong and Buzz Aldrin, on July 20, 1969, at 20:18 UTC. Armstrong became the first to step onto the lunar surface six hours later on July 21 at 02:56 UTC.eil Armstrong's certification: I certify that this World Scout Badge was carried to the surface of the Moon on man's first lunar landing, Apollo XI, July 20, 1969.. First Man on the Moon Commemorative Issue of 1969. Apollo 11 crew at the White House in 2004.
Detection of a specific molecule occurs on the outer surface of a receptor cell at a plasma membrane protein known as chemoreceptor. Generally, a chemoreceptor will detect just a single chemical or a small range of structurally similar chemicals.
Sensory Mechanism. 1  Experimental studies have demonstrated that the central chemoreceptors are most directly sensitive to changes in their surrounding extracellular fluid pH, which given their anatomical location would mean the CSF. 2  Carbonic Acid spontaneously releases a free hydrogen ion which reduces the pH of CSF.