A miniature ninja throwing star or a surgical device? The microgripper, shown here coming out of a catheter tube, is activated by body heat. The sharp appendages fold up when the device warms up. Evin Gultepe, Gracias Lab, Johns Hopkins University. hide caption

itoggle caption Evin Gultepe, Gracias Lab, Johns Hopkins University.

Three PhoneSats, like the one seen here during a high-altitude balloon test, were launched into space on Sunday. The slightly modified cellphone satellites cost a few thousand dollars in parts. NASA Ames Research Center hide caption

itoggle caption NASA Ames Research Center

A microscopy image of a rat pancreas shows the insulin-making cells in green. Masur/ hide caption

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Researchers are using small remote-controlled planes to survey the populations of the greater sage grouse. Stephen J. Krasemann/Science Source hide caption

itoggle caption Stephen J. Krasemann/Science Source

In this Jan. 18 photo provided by the NYU Langone Medical Center, a technician examines mice to determine their health at the hospital's complex in New York. New York University/AP hide caption

itoggle caption New York University/AP

Researchers used a clip from the David Lynch film Rabbits to make volunteers uneasy. Afterward some people got Tylenol, which appeared to help them cope. YouTube hide caption

itoggle caption YouTube

The small squares superimposed on this image of the Milky Way galaxy show where in the sky the Kepler telescope is hunting for Earth-like planets. Kepler, which launched in 2009, has identified more than 100 planets. NASA hide caption

itoggle caption NASA