An enclosed, pressurised habitat located on the surface of a planet, moon or asteroid. To protect against cosmic radiation, smaller domes have thick shells and often are partially or wholly covered in regolith.
Larger domes may be partially or wholly transparent, allowing light from the local star to enter for the purpose of plant growth. The atmosphere itself inside a large dome gives some protection against radiation; this is often augmented with magnetic or electrostatic shielding. A large dome may entirely fill a crater, and several domes may be connected together to form a continuous habitat, with a flexible roof held up by air pressure. A dome habitat which covers a significant part of a planet or other object is known as a worldhouse.