The Rock from Mars: A Detective Story on Two Planets

Hal Harris | Thu, 11/02/2006 - 01:00

If you've been reading Hal's Picks for a long time, you might remember something about this rock, ALH84001, because the publication in Science of the paper that announced evidence in a meteorite that life had once existed on Mars was my Pick back in August of 1996. The article was controversial, as you might expect. How do we know this rock, found in the ice of Antarctica, really came from Mars? How do we know that the critical isotopic ratios of its carbonates are the result of life, rather than inorganic processes? How do we know that it has not been altered during its time on earth? Many of these questions were raised ten years ago, and even more have beleaguered the authors since then. The story is much longer, richer, and more even more interesting than it first appeared. I recommend this book for students and teachers of science because Kathy Sawyer does such a good job of describing the adventure, the personalities, the political considerations, and the controversy surrounding this chunk of rock. It could easily inspire students to become scientists because it shows so clearly how the processes of science (including heated arguments) actually operate.