Seems the Earth may have third natural moon. The object, dubbed J002E2 (or J002E3, depending on the report), may have arrived recently, and is currently in a 50-day orbit. It still is undecided if it truly is a natural body or perhaps a piece of terrestrial space junk. The Earth’s second “moon”, called Cruithne, is apparently a Trojan asteroid scribing a horseshoe-like path.
Update 9/12: Looks like it could just be a Saturn V S-IVB stage, likely from Apollo 12.