Mj lnir: Impact Crater . ... 10.06.1999 . ... For example, this false color image produced from seismic data shows a recently discovered ringed structure about 24 miles wide on the floor of the Barents Sea . It is most probably the result of the impact, roughly 150 million years ago, of a mile or so wide asteroid-like body. ... Drawing on Norse mythology , the crater has been aptly named Mj lnir - Thor's hammer. ... NASA Web Site Statements, Warnings, and Disclaimers . ...