An artist's rendition of two Sinosauropteryx dinosaurs, showing their short, bristle-like feathers along the midline of the head, neck, back and around the tail, forming irregular stripes.
Chuang Zhao and Lida Xing
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.
This decorative shell ornament, attributed to Neanderthals, shows signs of being painted with orange pigment. It's one of several examples of ornamentation that researchers have found in Spain, at sites that were used by Neanderthals as far back as 50,000 years ago.
Courtesy of Joao Zilhao
A view of the central region of the Milky Way galaxy. Dark matter accounts for over 70% of the mass of the Milky Way, but because dark matter is invisible, all we see when we look up in the sky is a small amount of stars, planets and gas.
Our sense of time can be influenced by things like drinking coffee, or being on an adrenaline rush from an amusement park ride like this one at Dreamworld in Australia.
Bradley Kanaris/Getty Images