American Airlines, Inc. (AA) is a major American airline headquartered in Fort Worth, Texas, within the Dallas–Fort Worth metroplex. It is the world’s largest airline when measured by fleet size, revenue, scheduled passengers carried, scheduled passenger-kilometers flown, and a number of destinations served. American, together with its regional partners, operates an extensive international and domestic network with almost 6,800 flights per day to nearly 350 destinations in more than 50 countries. American Airlines is a founding member of the Oneworld alliance, the third largest airline alliance in the world. Regional service is operated by independent and subsidiary carriers under the brand name American Eagle.
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.
Other authors make similar assertions. In Our Mysterious Spaceship Moon (Dell, 1975), author Don Wilson publishes the following conversation between the Eagle crew and Mission Control, presumably picked up by ham radio operators during a broadcast interruption attributed by NASA to an "overheated camera":
The surface of our Moon's near-side is dominated by the bewildering and unique Procellarum region, and this area is characterized by numerous ancient volcanic plains, low elevations, and a strangely unique composition.