While jaws dropped at the news of Facebook’s $19bn purchase of WhatsApp, with many wondering how on earth Facebook hoped to see a return on its investment, reports that the social networking firm might be buying a drone company suddenly shed a whole lot of light on the long term ambitions for Zuckerberg and co. Reports swirled earlier this month that Facebook was in talks with Titan Aerospace, a company founded in 2012, which makes a series of solar powered autonomous planes that fly around six miles higher than airliners and are designed to stay airborne for up to five years (although that is unproven – the current record for Unmanned Aerial Vehicle (UAV) endurance is held by QinetiQ’s Zephyr,…