Four flying objects have been shot down over North America in the space of a week as the US military fails to rule out extra-terrestrial involvement. On the Sky News Daily podcast, Niall Paterson speaks to US correspondent James Matthews about the political motivation behind President Biden’s new trigger-happy approach to protecting US airspace and Nick Pope, who ran the UK governments' UFO programme, explains why these UFOs are far more likely to be from China than Mars. Producer: Rosie Gillott Interviews producer: Alex Edden Podcast promotions producer: David Chipakupaku Editor: Philly Beaumont