The bdelloid rotifer Philodina gregaria. Bdelloid rotifers are tiny invertebrates that reproduce asexually. Courtesy of Micrographia hide caption

itoggle caption Courtesy of Micrographia

An artist's rendering of a NASA Mars Exploration Rover on the surface of Mars. The robotic explorer Spirit has been stuck in sandy soil on Mars since April 2009. NASA/JPL-Caltech hide caption

itoggle caption NASA/JPL-Caltech

Researchers dyed sperm from each deer mouse a different color; in this case, red represents one male and green another. The sperm joined together with their own kind, as seen here, allowing them to swim faster than those that did not cluster together. Heidi Fisher hide caption

itoggle caption Heidi Fisher

A two-dimensional representation of E8 symmetry, the type of symmetry exhibited by particles in the study. John Stembridge hide caption

itoggle caption John Stembridge

Scientist turned director Valerie Weiss discusses a scene with cinematographer Jamie Urman on the set of her film, Losing Control. Courtesy of Richard Salazar hide caption

itoggle caption Courtesy of Richard Salazar

The revolutionary scientific work On the Origin of Species by Charles Darwin was published in 1859. Courtesy of Huntington Library hide caption

itoggle caption Courtesy of Huntington Library

A close-up composite image of a dust particle. The green patches contain bromine, calcium and/or iron. Courtesy of American Chemical Society hide caption

itoggle caption Courtesy of American Chemical Society

A team at NASA tests possible maneuvers for the Mars rover Spirit to use to escape the soft soil it has been stuck in since April. NASA/JPL-Caltech hide caption

itoggle caption NASA/JPL-Caltech