Fundamentally, momentum conservation is linked to invariance under space translations. See Noether's theorem. If you want to find a system that does not conserve momentum you should look for situations where space is not uniform, e.g. balls rolling on the surface of a bowl, a planetary system (when the dynamics of the sun is neglected), etc.
Socorro is a city in Socorro County in the U.S. state of New Mexico. It is in the Rio Grande Valley at an elevation of 4,579 feet (1,396 m). In 2012 the population was 8,906.
17.2 Persons per square kilometer is the population of New Mexico. It at present has a growth rate of 0.64% every year, that positions 30th in the nation. The last enumeration inside the United States was done in 2010 and that study demonstrated that the number of inhabitants in New Mexico was 2,059,179.