HMS Challenger set sail from England to study the world’s oceans on December 7th, 1872. Its accomplishments were so massive that it took 23 years and 30,000 pages to publish them all. Yet the job isn’t finished even now. Scientists look at its results to teach us how the oceans have changed in the 150 years since it headed out to sea.
Great whites, makos, blue sharks—these are a handful of the shark species that migrate thousands of miles each year, but scientists have struggled to figure out how these sharks know how to get where they’re going. A study with more than a dozen juvenile bonnethead sharks has finally offered some answers. Sharks, like sea turtles, appear to use the Earth’s magnetic field to navigate the seas.
