There already is a Mars Mod, although it is in the process of being updated to 1.8.1 now (I thought they were waiting until 1.9, but I might be thinking of the Mood Mod instead).
Anyway, if you want to continue with this mod, I'd suggest either picking another planet to base it off of OR at least renaming it (if you called it the Red Planet Mod, people would still associate it with Mars but at least you wouldn't confuse people as much). In the very least add a version number to your mod and specify what version of Minecraft it will work with once you have a release ready (look at how the titles are formatted in this section if you are wondering).
↑Mars Dirt Block
Blocks Will Add :
Mars Dirt
Mars Grass
Mars Ore?
Dry Ice
Portal Block (Or Teleport)
Coal Ore will Found 150% probability than Earth
Iron Ore will Found 150% probability than Earth
Items Will Add :
Blocks to Items
Mineral Item (Ore to Item) ?
Space Suit - make the mars ore ?
Mars Prove - robot ?
Environment :
Mars Sun will 1/2 nomal Sun Size
Jupiter will 1/16 nomal Sun Size.
Earth will 1pixel
Saturn will 4pixel
Day Sky will white
night Sky will more black
non moonlight
12 Light Level (distance from the sun is far than Earth)
SandStome
territory
cave
ravines (bigger than Earth) it will 200% probability than Earth
Ancient ruins (stronghold)
mountains (bigger than Earth too)
Ice layer in between the Dirt and Stone layer (permafrost)
no lava (I heared Mars was cooling and Core is trans the Soild rock and metal)
Mars plants
Dry Lake
Dry River
Dry Oceon
underground water will exist.
Biome
Mars Plants Land (Like Forest)
Extreme Hills biome(mountain biome)
Dry River
Dry Oceon
plains
Dryice land (Tuntra)
*sorry to short post!
*I can' English well.
Anyway, if you want to continue with this mod, I'd suggest either picking another planet to base it off of OR at least renaming it (if you called it the Red Planet Mod, people would still associate it with Mars but at least you wouldn't confuse people as much). In the very least add a version number to your mod and specify what version of Minecraft it will work with once you have a release ready (look at how the titles are formatted in this section if you are wondering).