Wreck of the RMS Titanic research. The stern section, which had previously received relatively little attention from explorers, was specifically targeted for analysis. The microbial colonies aboard "Titanic" were also a key focus of investigation. The second expedition, from 27 May – 12 June 2004, saw the return of Robert Ballard to "Titanic" nearly 20 years after he discovered it. The expedition spent 11 days on the wreck, carrying out high-resolution mapping using video and stereoscopic still images. 2005 saw two expeditions to the "Titanic". James Cameron returned for the third and last time to film "Last Mysteries of the Titanic". Another expedition searched for
Atlantic Ocean and the Southern Ocean in the south (other definitions describe the Atlantic as extending southward to Antarctica). The Equatorial Counter Current subdivides it into the North Atlantic Ocean and the South Atlantic Ocean at about 8°N. Scientific explorations of the Atlantic include the Challenger expedition, the German Meteor expedition, Columbia University's Lamont-Doherty Earth Observatory and the United States Navy Hydrographic Office. The oldest known mentions of an "Atlantic" sea come from Stesichorus around mid-sixth century BC (Sch. A. R. 1. 211): "Atlantikoi pelágei" (Greek: Ἀτλαντικῷ πελάγει; English: 'the Atlantic sea'; etym. 'Sea of Atlantis') and in "The Histories" of Herodotus