The special thing about the coin is the authentic piece of the Chelyabinsk meteorite inlaid on the reverse. Considered the largest meteor since 1908, it exploded on February 15th, 2013 over Chelyabinsk in the Russian Ural region. A piece of the meteorite hit Lake Tschebarkul not far from Chelyabinsk tearing a hole of about six meters in diameter in the ice sheet.