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
Dora the Explorer: Journey to the Purple Planet the top of the tall mountain. When they reach the top of the mountain, the group launch themselves into outer space. Dora, Boots, and the aliens are required to find 4 colored space keys on different planets to unlock the Space Door to the Purple Planet. First, they find the Green Key on the slimy Green Planet. Next, they go to bubbly and musical Yellow Planet to find the Yellow Key. Then, they go to the windy and nebular Blue Planet to find the Blue Key. Last, they find the Red Key on the mechanical Red Planet. After opening the