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:For Rosetta, a Landing and an Ending on a CometResearchers Make Progress Toward Identifying C.T.E. in the LivingQ&A: Organic Milk Will Wait and Wait for YouLIVE: NASA to reveal ‘surprising activity’ on Jupiter’s Europa in historic announcementReactions: Letters to the EditorA New Debate Over Pricing the Risks of Climate Change