This artist's concept is called 20/20 Vision. Did life ever exist on Mars? If so, the best evidence may be fossils preserved in the rocks. Geologists and biologists will one day explore Mars, piecing together the history of the planet and perhaps its ancient life. Note: NASA currently has no formal plans for a human expedition to Mars or the Moon. This image and others displayed may not reflect the hardware and overall concept of possible visits to either of those celestial bodies. However, the art work represented here serves as a comprehensive study of various concepts and ideas developed as possibilities over a period of years.