One of our scientists, Dr. Assaf Vardi, is off on a month-long cruise. He is on the Knorr, a research vessel operated by the Woods Hole Oceanographic Institute, with a team from the Weizmann Institute and another four research teams on a route that will take them from the Azores to Iceland. On the way, they will be sampling the plankton; among other things they want to understand how the molecular processes that take place in these single-celled organisms affect everything from the ocean's food chain to the oxygen in the atmosphere. Rose Eveleth is posting from the ship daily on the…