You may want to try posting on the RC SPS ID forum and see what answers you get. My best early guess would be A. Hyacinthus, but that definitely could be wrong. Red Planet has become a pretty uniform name to describe acros that are red to pink in colour with a green base and tend to plate or table, which most think is A. Hyacinthus. There is a lot of variation in these pieces and you'll find "Red Planet" everywhere but its not all from the same mother colony. Even within the same tank, clones can show some variation based on the light and flow they are in. Just because it doesn't look like your other red planet doesn't necessarily mean it isn't the same or similar species of coral however. Difficult to say though based on its current growth. Hopefully you get a better answer and more definitive ID. Either way, nice SPS