1.   Among the controversies are interpretations of images taken from the most recent mission to map the Martian terrain from orbit.

2.   According to Hoffman, the collapse of unstable Martian terrain, such as steep-sided craters, released liquid carbon dioxide that had been locked away underground.

3.   Mars has polar ice caps and images of the Martian terrain taken by previous orbiters show signs that the planet once had plenty of water flowing on the surface.

4.   Once ejected, the landers successfully reached the Martian terrain using aeroshells, parachutes and braking rockets.

5.   The dusty rocks of the rust-colored Martian terrain are the liveliest elements in this appallingly scripted sci-fi rescue movie.

6.   The oldest Martian terrain bears the scars of extensive cratering by meteors.

7.   The Viking missions, which included a pair of orbiting spacecraft that gathered thousands of photographs of the Martian terrain, produced no evidence of life.

8.   The Martian terrain is very diverse, including rocky deserts, valleys, fissures, volcanoes and mountain chains.