Lava glows bright red—an indication of superhot temperatures—in a false-color satellite image of Russia's Tolbachik Volcano taken on December 1.

In late November, Tolbachik—located on the Kamchatka Peninsula (map)—began erupting for the first time in 36 years. Tolbachik is a shield volcano: a low-profile, broad structure with a shape resembling an ancient warrior shield, according to NASA's Earth Observatory.