Martian Martian A Martian is a native inhabitant of the planet Mars. Although the search for evidence of life on Mars continues, many science fiction writers have imagined what extraterrestrial life on Mars might be like. Some writers also use the word "Martian" to describe a human colonist on Mars. The earliest known instances of the word "Martian", used as a noun instead of an adjective, were printed in late 1877. They appeared nearly simultaneously in England and the United States, in magazine articles detailing Asaph Hall's discovery of the moons of Mars in August of that year. The next event
Ice planet Ice planet An ice planet is a theoretical type of exoplanet with an icy surface of volatiles such as water, ammonia, and methane. Ice planets consist of a global cryosphere. They are bigger versions of the small icy worlds of the Solar System, which includes the moons Europa, Enceladus, and Triton, the dwarf planets Pluto and Eris, and many other small Solar System bodies such as comets. Ice planets usually appear nearly white with geometric albedos of more than 0.9. An ice planet's surface can be composed of water, methane, ammonia, carbon dioxide (known as "dry ice"), carbon monoxide, and