Plankton make up 98 percent of the biomass of ocean life and provide half of the oxygen on the planet. Scientists are working to figure out how climate change may be affecting these important microorganisms. M. Ormestad/Tara Oceans hide caption

itoggle caption M. Ormestad/Tara Oceans

Polar bears in the Beaufort Sea in northern Alaska. Scientist Charles Monnett caused a stir with a 2006 report on polar bears that were drowning, apparently owing to a lack of ice. Steve Amstrup/Fish and Wildlife Service hide caption

itoggle caption Steve Amstrup/Fish and Wildlife Service

Bats harbor many types of coronaviruses and were probably the original source of the new coronavirus that appeared in the Middle East. iStockphoto.com hide caption

itoggle caption iStockphoto.com

NASA says it has found proof that water shaped the rocks on the left, in a photograph taken by the Mars rover Curiosity (left). For comparison, the agency released an image of rocks from Earth (right). NASA hide caption

itoggle caption NASA

The Emperor's Himalayan lavender tea is popular at Washington, D.C.'s Park Hyatt Tea Room, but please don't put milk in it. Courtesy of Park Hyatt hide caption

itoggle caption Courtesy of Park Hyatt

NASA says it has found proof that water shaped the rocks on the left, in a photograph taken by the Mars rover Curiosity (left). For comparison, the agency released an image of rocks from the Earth (right). NASA hide caption

itoggle caption NASA