A graduate of Purdue University, Armstrong studied aeronautical engineering; his college tuition was paid for by the U. S. Navy under the Holloway Plan. He became a midshipman in 1949 and a naval aviator the following year. He saw action in the Korean War, flying the Grumman F9F Panther from the aircraft carrier USS Essex. In September 1951, while making a low bombing run, Armstrong’s aircraft was damaged when it collided with an anti-aircraft cable which cut off a large portion of one wing. Armstrong was forced to bail out. After the war, he completed his bachelor’s degree at Purdue and became a test pilot at the National Advisory Committee for Aeronautics (NACA) High-Speed Flight Station at Edwards Air Force Base in California. He was the project pilot on Century Series fighters and flew the North American X-15 seven times. He was also a participant in the U. S. Air Force’s Man in Space Soonest and X-20 Dyna-Soar human spaceflight programs.
The astronomers then conducted an analysis called a Bouger correction in order to subtract the gravitational effect of topological features, such as valleys and mountains, from the total gravity field. What is then left is the gravity field hidden beneath the lunar surface, existing within its crust. "The near-side of the Moon has been studied for centuries, and yet continues to offer up surprises for scientists with the right tools. We interpret the gravity anomalies discovered by GRAIL as part of the lunar magma plumbing system--the conduits that fed lava to the surface during ancient volcanic eruptions," Dr. Maria Zuber explained in an October 1, 2014 NASA Press Release. Dr. Zuber is from the Massachusetts Institute of Technology (MIT) in Cambridge. Comets are really traveling relic icy planetesimals, the remnants of what was once a vast population of ancient objects that contributed to the construction of the quartet of giant, gaseous planets of the outer Solar System: Jupiter, Saturn, Uranus, and Neptune. Alternatively, the asteroids--that primarily inhabit the region between Mars and Jupiter termed the Main Asteroid Belt--are the leftover rocky and metallic planetesimals that bumped into one another and then merged together to form the four rocky and metallic inner planets: Mercury, Venus, Earth, and Mars. Planetesimals of both the rocky and icy kind blasted into one another in the cosmic "shooting gallery" that was our young Solar System. These colliding objects also merged together to create ever larger and larger bodies--from pebble size, to boulder size, to mountain size--and, finally, to planet size.