|PROGRAM & MISSIONS| The Mars Exploration Program's Science
Theme The Mars Exploration Program is a science-driven program
that seeks to understand whether Mars was, is, or can be, a
habitable world. To find out, we need to understand how
geologic, climatic, and other processes have worked to shape
Mars and its environment over time, as well as how they interact
today. Mars is similar to Earth in many ways, having many of the
same "systems" that characterize our home world. Like Earth,
Mars has an atmosphere, a hydrosphere, a cryosphere and a
lithosphere. In other words, Mars has systems of air, water,
ice, and geology that all interact to produce the Martian
environment. What we don't know yet is whether Mars ever
developed or maintained a biosphere--an environment in which
life could thrive. The key to understanding the past, present or
future potential for life on Mars can be found in the four
broad, overarching goals for Mars Exploration: