You are currently viewing the summary.
View Full TextLog in to view the full text
AAAS login provides access to Science for AAAS members, and access to other journals in the Science family to users who have purchased individual subscriptions.
More options
Download and print this article for your personal scholarly, research, and educational use.
Buy a single issue of Science for just $15 USD.
Summary
Somewhere in the sediments and rocks beneath the ocean floor, it gets too hot for living things. But how far down? Even after drilling kilometers into the ocean floor, scientists have found that microbes persist. Rather than going for depth, then, a new drilling expedition embarking this month off the coast of Japan will search for the high temperature at which microbial life stops in the deep biosphere. Part of the International Ocean Discovery Program, the T-Limit campaign could guide estimates of the abundance and diversity of ocean floor microbes, which play large roles in biogeochemical cycles. Demonstrating the absence of life will be challenging, however, and push the limits of existing methods.
