Victoria Ruiz (left), a postdoctoral fellow in immunology, works with Brianna Delgado, a high school student that she mentors, at the Blaser Lab, inside NYU's Langone Medical Center in New York, NY. Ramsay de Give for NPR hide caption

itoggle caption Ramsay de Give for NPR

Medical workers at the John F. Kennedy Medical Center in Monrovia, Liberia, put on their protective suits before going to the high-risk area of the hospital, where Ebola patients are being treated, Sept. 3. Dominique Faget/AFP/Getty Images hide caption

itoggle caption Dominique Faget/AFP/Getty Images

Closeup of Philae's primary landing Site J, which is located on the "head" of Comet 67P/Churyumov–Gerasimenko. The image was taken by Rosetta's OSIRIS narrow-angle camera on Aug. 20. ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA hide caption

itoggle caption ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

A species of peach related to the 7,500-year-old pits found in China recently (left), and today's more modern versions (right). Courtesy of Jose Chaparro/University of Florida hide caption

itoggle caption Courtesy of Jose Chaparro/University of Florida

A contentious piece of clothing: Members of the Iranian women's soccer team celebrate their win over Syria back in 2007. That year, the international soccer league FIFA banned the wearing of hijabs during games. The ban was lifted in July. Mohammad Abu Ghosh/AP hide caption

itoggle caption Mohammad Abu Ghosh/AP

Tom Murphy, 56, in his home in Gainesville, Va., was diagnosed with ALS four years ago. An experimental drug seems to have slowed the progression of his disease, he says, though most ALS patients aren't as lucky. T.J. Kirkpatrick for NPR hide caption

itoggle caption T.J. Kirkpatrick for NPR

Yes, indeed, cows can leap. Here, Regina Mayer jumps with her cow Luna — yes, Luna — over a hurdle in southern Germany, in 2011. Kerstin Joensson/AP hide caption

itoggle caption Kerstin Joensson/AP