Photos: Science, medicine and the environment

This picture provided by NASA captures the glowing green beauty of the Aurora Borealis. Looking northward across the Gulf of Alaska, over a low pressure area, the aurora brightens the night sky. This week, a fleet of five small satellites, called Themis, observed the beginning of a geomagnetic storm. Their observations gave credence to the theory that magnetic explosions about one-third of the way to the moon cause the northern lights, rather than ones occurring closer to the Earth.   (NASA / AFP/Getty Images)

Bones of a mammoth are displayed near Belarus workmen digging the foundation of a building in Minsk. The workmen dug up the bones during construction. Scientists estimate that the remains are approximately 12,000 years old.  (Viktor Drachev / AFP/Getty Images)

This satellite photo released by the National Snow and Ice Data Center at the University of Colorado at Boulder shows the Wilkins Ice Shelf on March 6, 2008 on the Southwest Antarctic Peninsula as it began to break apart. The ice shelf, about seven times the size of Manhattan began collapsing on Feb. 28, putting an even greater portion of glacial ice at risk, scientists said Tuesday. NSIDC processed these images from the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, which flies on NASA’s Earth Observing System Aqua and Terra satellites.  (National Snow and Ice Data Center/NASA, Associated Press)