A thermoelectric PowerCard like this one can be used to convert waste heat into an electric power source, Alphabet Energy says. Alphabet Energy hide caption

itoggle caption Alphabet Energy

Can people tell a computer-generated story from a human-authored one? How about a poem, or a playlist? Three new contests hope to find out. ImageZoo/Corbis hide caption

itoggle caption ImageZoo/Corbis

The sea snail Conus magus looks harmless enough, but it packs a venomous punch that lets it paralyze and eat fish. A peptide modeled on the venom is a powerful painkiller, though sneaking it past the blood-brain barrier has proved hard. Courtesy of Jeanette Johnson and Scott Johnson hide caption

itoggle caption Courtesy of Jeanette Johnson and Scott Johnson

Researcher John Clements in the early 1980s, after he figured out that lungs need surfactants to breathe. David Powers/Courtesy of UCSF hide caption

itoggle caption David Powers/Courtesy of UCSF

Harry Kroto, pictured in 1996, displays a model of the geodesic-shaped carbon molecules that he helped discover. Michael Scates/AP hide caption

itoggle caption Michael Scates/AP

The Cryptsporidium parasite emerges from the oocyst ready to infect. Muthgapatti Kandasamy & Boris Striepen/Courtesy of University of Georgia hide caption

itoggle caption Muthgapatti Kandasamy & Boris Striepen/Courtesy of University of Georgia

This is a calculated flood map for the city of St. Louis. Water depth goes from deep (dark blue) to shallow (white, light blue). Floodwater can come from the Illinois, Upper Mississippi and Missouri rivers, as well as from heavy local precipitation. Courtesy of Dag Lohmann/Katrisk hide caption

itoggle caption Courtesy of Dag Lohmann/Katrisk

The 200-inch Hale Telescope, a masterpiece of engineering at Caltech's Palomar Observatory, was the world's largest telescope until 1993. Scott Kardel/Palomar Observatory/Courtesy of Palomar Observatory/California Institute of Technology hide caption

itoggle caption Scott Kardel/Palomar Observatory/Courtesy of Palomar Observatory/California Institute of Technology

An artist's rendition of the HD 7924 planetary system — just 54 light-years away from Earth — shows newly discovered exoplanets c and d, which join Planet b. Karen Termaura, BJ Fulton/UH IfA hide caption

itoggle caption Karen Termaura, BJ Fulton/UH IfA

The Hooker 100-inch reflecting telescope at the Mount Wilson Observatory, just outside Los Angeles. Edwin Hubble's chair, on an elevating platform, is visible at left. A view from this scope first told Hubble our galaxy isn't the only one. Courtesy of The Observatories of the Carnegie Institution for Science Collection at the Huntington Library, San Marino, Calif. hide caption

itoggle caption Courtesy of The Observatories of the Carnegie Institution for Science Collection at the Huntington Library, San Marino, Calif.