The red arc in this infrared image from NASA's Spitzer Space Telescope is a giant shock wave, created by a speeding star known as Kappa Cassiopeiae. It is a massive, hot supergiant moving at around 2.5 million mph relative to its neighbors (1,100 kilometers per second). But what really makes the star stand out is the surrounding, streaky red glow of material called a bow shock, in its path. (Image Credit: NASA/JPL-Caltech)
Footprints of a Cabypara are seen on the cracked grounds of the Jaguari dam in Joanopollis, 136 km (77 miles) from Sao Paulo, Brazil.
Ukraine's President Viktor Yanukovych shakes hands with opposition leader Vitaly Klitschko (L) after signing an EU-mediated peace deal, aiming to end a violent standoff that has left dozens dead and opening the way for an early presidential election this year, at the presidential headquarters in Kyiv.
A view of the Delta IV rocket streaking across the sky after launching from Cape Canaveral Air Force Station is seen from Port Canaveral, Florida, Feb. 20, 2014.