Searching for Life on Early Mars: Lessons from the Pilbara

Stromatolites in the Pilbara region of Western Australia constitute the earliest outcrop-scale evidence of life on Earth (Figure 1). The stromatolites in the 3.4 Ga Strelley Pool Formation (SPF) provide an important analog for searching for fossil evidence of early life on Mars, as Noachian aged sediments on Mars were formed under similar environmental conditions. Stromatolites represent possibly the best evidence that could be collected by a rover because they form recognizable macroscopic structures and are often associated with chemical and microscopic evidence.