Willem de Kooning's Woman — Ochre (oil on canvas, 1954-55) has been missing for 30 years. University of Arizona Museum of Art hide caption

An illustration shows what a helicopter drone would look like on the surface of Mars. NASA/JPL-Caltech hide caption

A view from the starting line of the sixth annual Krispy Kreme Challenge in Raleigh, N.C., in 2010. The local children's health clinic takes its name from this annual charity race, which draws about 8,000 participants each year. Courtesy of Dustin Bates hide caption

Coal fires burn early in the morning in January 2014 at a privately owned coal mine in India's Jharkand state, making the air dense with noxious smoke and dust. Forty percent of India's mineral wealth lies in Jharkhand. Johnny Haglund hide caption

Carol Miller, 68, and Marge Klindera, 79, are here to help — and have been for many years now. "People say, 'You mean you've given up Thanksgiving for all these years?' " Miller remarks. "And I never feel like I've ever given anything up." StoryCorps hide caption

This year's flu vaccine protects against a few different virus strains, including the H1N1 seen here. The fuzzy outer layer is made of proteins that allow the virus to attach to human cells. NIAID/Flickr hide caption