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.
1 Socorro, SÃ£o Paulo, a city in SÃ£o Paulo state, Brazil. 2  Socorro (district of SÃ£o Paulo), a district in SÃ£o Paulo city, Brazil. 3  Socorro River, a river in Rio Grande do Sul state in southern Brazil.  Socorro Island, an older name for Guamblin Island, Chile.