"Arkas initially appeared through the telescope as a fuzzy light brown ball due to it's thick sandy atmosphere, which scientists assumed was just a smudge on the lens. After years of attempting to clean the lens they replaced the telescope entirely, only to discover that the smudge was still there. It took several more months before they realized that the smudge on their lens was actually a planet."

Arkas is smaller than Kerbin and even Laythe, having a radius of approximately 0.71 Kerbin radii and exactly 0.85 Laythe radii. Arkas' surface is covered in sandy dunes as well as large, yet inactive volcanoes. Arkas has a golden colored atmosphere with an unknown composition, although the atmosphere is quite dense for a body it's size, having an atmospheric pressure greater than both Kerbin and Eve. Arkas' atmosphere extends up to 80km which is strange considering Arkas lacks the gravitational pull to keep such a dense atmosphere.

Arkas also features 17 unique biomes to explore, with biomes for the moons planned for the next update.

Arkas was created and was initally developed by user CoriW on the Kerbal Space Program forums, but development has passed on to The White Guardian on the KSP forums, the author of Planet Cyran. Since then two moons have been added to Arkas to further enlarge Arkas' system.