Editor's Note: Journalist and crew member Kathryn Eident and scientist Jeremy Jacquot are traveling on board the RV Atlantis on a monthlong voyage to sample and study nitrogen fixation in the eastern tropical Pacific Ocean, among other research projects. This is the sixth blog post detailing this ongoing voyage of discovery for ScientificAmerican.com .

Imagine you’re in space, floating high above the Earth. Picture the world’s oceans, glimmering sapphire under the heat of the sun and the protection of the ozone layer. Look closer, there’s a patch of brown in the middle of all that blue. It’s a bloom of phytoplankton called Trichodesmium , a “world famous” nitrogen fixer. [More]