I also just finished watching the first half of Aldnoah.Zero, with the second half coming out in 2015. It's an anime series where humans colonize Mars via a newly discovered portal/gate on the moon, and the Mars migrants (Called Martians from now on), find alien technology there that allows them to be independent from Earth as they separate. War breaks out between the two and ends with the destruction of the gate, cutting contact between both planets for fifteen years, until the daughter of the current leader of Mars visits earth in a message of peace is assassinated. It's a mecha anime with more serious political overtones.
It was a very interesting season, a lot of twists and turns. I'd definitely recommend it, especially if you like Gen Urobochi's other works (Fate/Zero, Madoka), ...And maybe i'd even suggest it more if you have no idea who he is!