Teams of volunteer archaeologists travel to Vindolanda during each excavation season. They painstakingly scrape and brush away at the soil to see what they can find. Rich Preston/NPR hide caption

itoggle caption Rich Preston/NPR

Surveillance camera images issued by the Metropolitan Police show thieves entering and leaving the scene of the burglary of the Hatton Garden Safe Deposit company. Police arrested seven suspects Tuesday. Metropolitan Police/PA Photos /Landov hide caption

itoggle caption Metropolitan Police/PA Photos /Landov

A campaign poster in Dublin encourages voters to say no to same-sex marriage ahead of a referendum in Dublin on Friday. Paul Faith/AFP/Getty Images hide caption

itoggle caption Paul Faith/AFP/Getty Images

A Proton-M rocket shown in 2013. The same type of rocket malfunctioned in mid-flight on Saturday and crashed over Siberia carrying a Mexican communications satellite. PHOTO ITAR-TASS/ITAR-TASS/Landov hide caption

itoggle caption PHOTO ITAR-TASS/ITAR-TASS/Landov

The headless, reclining sculpture of the river god Ilissos is on display at the State Hermitage Museum as part of its 250th anniversary celebration in St. Petersburg in December. The sculpture, taken from the Parthenon in Athens 200 years ago, was on loan to Russia from the British Museum. Grigory Dukor/Reuters/Landov hide caption

itoggle caption Grigory Dukor/Reuters/Landov

The view of the universe known as the Hubble Deep Field, presented in 1996, shows classical spiral and elliptical shaped galaxies, as well as a variety of other galaxy shapes. NASA/AP hide caption

itoggle caption NASA/AP