Harvard professor explains we may have ALREADY been visited by aliens for THIS reason ALIENS may have already visited Earth without us even noticing, according to a top Harvard professor. Share: Facebook Twitter Google+ Stumble Digg Email ThisBlogThis!Share to XShare to Facebook Related Posts:Times Insider: To Tell the Story of Biodiversity Loss, Make It About HumansJeff Bezos’ Blue Origin to get humans to the MOON by 2024 ‘and this time to STAY’Global Health: Gilead Will Donate Truvada to U.S. for H.I.V. PreventionTime travel SHOCK: How Brian Cox PROVED Albert Einstein’s special theory – 'It's possible'NASA and SpaceX: Could FAILED Dragon parachute test spell trouble for Elon Musk?Crossing the Atlantic in a Giant Barrel