Settled by one of the wealthiest nations at the time - Mexico -, it was named something else at one point. But after it was rediscovered, it was renamed Madero, after the extremely ineffective leader who's death marked the most violent period in the Mexican Revolution.
Madero's status as a habitable desert planet may not fit such a name, but the violence and illegal activities that happen here might. Run by warring drug cartels, the Federation's inability to establish order in the Imperial System allows the criminal element to flourish.
Populated by various settlements pockmarked across the planet, it is ironically the second wealthiest nation in the system due to the drug trade.
Smugglers and criminals alike often call it the "Mexico of Space". No one knows why, since it's so peaceful down there.