From left: Sekou Sheriff, of Barkedu village in Liberia, whose parents died at an Ebola treatment center; a polio vaccination booth in Pakistan; a schoolgirl in Ethiopia examines underwear with a pocket for a menstrual pad; an image from a video on the ethics of selfies; Consolata Agunga goes door-to-door as a community health worker in her village in Kenya. From left: John Poole/NPR; Jason Beaubien/NPR; Courtesy of Be Girl Inc.; SAIH Norway/Screenshot by NPR; Marc Silver/NPR hide caption
We all struggle with healthy habits — including experts. They just have science-tested tips to get them back on track. Michael Driver for NPR hide caption
The discovery of several of the heaviest elements, including tennessine, was confirmed at the Joint Institute For Nuclear Research in Dubna, Russia. SVF2/Universal Images Group via Getty hide caption
He Jiankui, a Chinese researcher shown here at a conference last year in Hong Kong, has been sentenced to three years in prison. Kin Cheung/AP hide caption
The total solar eclipse on August 21, 2017, photographed at Mary's River Covered Bridge, in Chester, IL, USA. Getty Images hide caption
An image of Ow Luen from his file, originally held at the USCIS, now available at the National Archives. Grant Din/National Archives hide caption
Humpack whale NOAA hide caption
Children play around trees downed by Cyclone Idai at the Guara Guara resettlement site in Mozambique, where thousands of people are still living more than nine months after the storm. NicholeSobecki/VII for NPR hide caption
The moon moves in front of the sun in a rare "ring of fire" annular solar eclipse, as seen in the sky over Singapore on Thursday. Louis Kwok/AFP via Getty Images hide caption
The first-ever image of a black hole at the center of galaxy M87, outlined by emission from hot gas swirling around it. EHT Collaboration hide caption
Scientists tested high-traffic areas of an airport to find out where germs are most likely to thrive. Getty Images hide caption
Victoria Gray, who has sickle cell disease, volunteered for one of the most anticipated medical experiments in decades: the first attempt to use the gene-editing technique CRISPR to treat a genetic disorder in the United States. Meredith Rizzo/NPR hide caption
Joey Clawson at one of his Christmas tree stands on the first day of harvest. He grows about 95,000 firs on his operation. Irina Zhorov for WHYY hide caption
Women of the Treatment Action Campaign and are affected by the HIV virus campaign for the use of Dolutegravir (DTG) at the International Aids Conference at the RAI Amsterdam Convention Centre. Gareth Fuller/PA Images/Getty Images hide caption