Lego Space Space subtheme in which the entire theme is "good", "bad", or "civilian". Life on Mars is a space theme released in 2001, around a time of increased curiosity about the red planet. The theme revolved around the concept of the lifeforms that could possibly exist on Mars. This was the first Space theme to feature two types of minifigures: human astronauts and Martian aliens. The sets denote peaceful coexistence between the two species on the planet Mars. The "Life on Mars" theme pioneered several unique aspects in Lego in general. It was the first Lego theme to utilize a pneumatic
Earthling English "yrþling", in the meaning "ploughman". The sense of "inhabitant of earth" is first attested in the 1590s. Its use in science fiction dates to 1949, in "Red Planet" by Robert A. Heinlein. The word "Human" has the same imposed meaning, since it originates from a PIE word "*ǵʰmṓ" "earthling" < "*dʰéǵʰōm" "earth". Compare Latin "homo" "human" and "humus" "earth, soil". Its modern use in science fiction literature contrasts "Earth" (the planet) with outer space or hypothetical other planets with sapient life. The term was often used in 1950s science fiction film and novels by aliens to express a disdainful