Many of life's building blocks can be found in the objects bombarding Earth from outer space. Does that mean that life, too, developed elsewhere before arriving here? Mary P. Hrybyk-Keith/NASA hide caption

toggle caption Mary P. Hrybyk-Keith/NASA

For centuries, Russians believed putting a brown frog in their milk would keep it fresh. Now scientists are finding chemicals in the frog's slimy goo that inhibit the growth of bacteria and fungi. Stefan Arendt/Corbis hide caption

toggle caption Stefan Arendt/Corbis

Moss and a cup fungus growing amid the decomposing leaves of Shakerag Hollow in Sewanee, Tennessee. Courtesy of David Haskell hide caption

toggle caption Courtesy of David Haskell

NPR thanks our sponsors

Become an NPR sponsor