An enormous mechanical snail crawls across a barren moon, its shell a tiered arcology of concentric rings. The rings rotate independently, generating power from the snail's movement. The shell's surface is a patchwork of solar panels, hydroponics bays, and industrial complexes. The snail's body is a segmented, flexible factory, processing the moon's regolith into building materials. Its eyestalks are towering observation posts, topped with domed command centers. A thruster array at the tail allows for space travel between celestial bodies. Angled view from the front, emphasizing the scale against the curved moon horizon. Hard sci-fi technical illustration style with a color scheme of metallic silvers, regolith grays, and pops of warning yellows and reds,