Uhm... Honestly, I did not spend a lot of time on Earth, so it's a bit hard to say.

[ The time she was on Earth was more often than not spent tending to the wounded of various fights, but that's... not a nice subject to breach and Atra doesn't elaborate. ]

The main difference is that Mars is poor, I... guess? Earth is the home of the wealthy, those in the colonies tend to have far less. There's a movement to change this! Wonderful people are working on improving conditions for us. But it's still... well, it's notable.