Drilling deep to study the oxygenation of Earth
Some 2.3 to 2.4 billion years ago, Earth underwent a monumental transformation that forever altered the planet's course. Cyanobacteria evolved a new kind of photosynthesis that unleashed tremendous amounts of oxygen into the oceans and atmosphere, setting the stage for life as we know it. The oxygenation of the planet, known as the "Great Oxygenation Event" or GOE, was undeniably monumenta