The soldiers that Mog sends to earth are sent on missions with the assigned tasks of protecting and caring for the people and cities there, but only with countries that are allied with the Empire.
An aeromorph was sent to the city of Brasilia with the assigned task of protecting the inhabitants of the city, as Brazil has recently joined the alliance, this would be the first time that a macro soldier has set foot on Brazilian soil
(Lets hope the soldiers with their universal translator can understand Portuguese)