About 16 million years ago, a rock from Mars began sailing through space, dislodged from its home by a comet or asteroid. Eventually, about 19,000 years ago, it fell onto the frozen wastes of Antarctica. There it rested undisturbed until 1984, when a NASA researcher, combing the ice for meteorites, picked it up and was immediately struck by its unusual greenish-gray cast. The field notes describing the rock ended with an unscientific "Yowza-Yowza."
"Yowza" was an under-statement. The little Mars rock would soon become an international celebrity, touching off a fierce debate about the possibility of life on Mars, the origins of life on Earth and, in the end, the definition of life itself. Weighing just over 1.8kg, it would manage to pull into its orbit the head of NASA, former US president Bill Clinton and former US vice president Al Gore, Carl Sagan, an all-star cast of scientists from at least a half-dozen different disciplines and a pricey call girl named Sherry Rowlands.
Kathy Sawyer, in The Rock From Mars, offers a popularized yet meticulously researched chronicle of the Mars rock's short life in the public eye. But the rock itself is a MacGuffin. Sawyer's real story is the drama of high-stakes science and the way big discoveries can quickly devolve into a messy argument over money, politics and professional status. A lot was riding on the rock, and the infighting, among scientists and bureaucrats alike, often turned vicious. "I want to sit up front," one scientist said as he arrived at a debate between two Mars rock opponents. "I want to see the spittle."
The rock, initially misidentified after being delivered to NASA laboratories near Houston, lay in storage with run-of-the-mill meteorites for years. By chance, a researcher using an electron microscope in 1993 realized that he was looking at a Mars rock. That in itself was cause for celebration, since only a few rocks from Mars have been found on Earth, but there was more to come. The rock, it turned out, was formed 4.5 billion years ago, making it the oldest known rock from any planet.
Even more intriguing, the rock, apparently formed from volcanic flow that cooled when Mars was still in its infancy, contained an unusually high concentration of carbon compounds, deposited by carbonated water at moderate temperatures -- moderate enough for life to exist. Further study showed that the rock contained organic compounds sometimes associated with life, and mysterious squiggles that resembled the fossils of dead bacteria.
The meaning of those little squiggles -- particularly a segmented Tootsie-Roll shape that quickly became known as "the worm" -- bedeviled scientists at NASA and, as the findings were made public, their colleagues around the world. Sawyer, a former science reporter for The Washington Post, takes a fly-on-the-wall approach as she follows, in sometimes numbing detail, the slow work of observation leading to new hypotheses, some plausible, some seemingly fantastic. Did meteorites from Mars, carrying primitive life forms, create life on Earth? Or as Richard Zare, a laser chemist who worked on the rock, put it, "Is it possible that actually we're all Martians?"
William Schopf, an eminent paleobiologist and authority on early life forms on Earth, had an answer to that question: no. He quickly emerged as the most severe critic of the NASA team and of the idea that the Mars rock contained living material. How did NASA know that the worm and the other fossil-like bits were not formed by inorganic processes? Where were the cell walls? The "giggle factor," NASA's greatest fear, looked as though it might be gathering momentum. Life on Mars? Why not show slides of little green men?