Mystery still surrounds the latest flying objects shot down by the US over northern Alaska, Canada’s central Yukon territory and Lake Huron in Michigan in the last week. Unlike the suspected Chinese surveillance balloon that was shot down off the coast of South Carolina on 4 February, US authorities have been mostly unwilling to speculate on where the last three objects originate from – or even to characterise what they are. However, according to CBS’s veteran national security correspondent, David Martin, officials have apparently not ruled out whether at least some of the unidentified aerial objects were so-called “sky trash”....