Investigating Earth´s earliest life
(World News Science)

In the second grade, Kelsey Moore became acquainted with geologic time. Her teachers instructed the class to unroll a giant strip of felt down a long hallway in the school. Most of the felt was solid black, but at the very end, the students caught a glimpse of red. That tiny red strip represented the time on Earth in which humans have lived, the teachers said. The lesson sparked Moore`s curiosity. What happened on Earth before there were humans? How could she find out? A little over a decade later, Moore enrolled in her first geoscience class at Smith College and discovered she now had the tools to begin to answer those very questions. Moore zeroed in on geobiology, the study of how the...