Last week, Nasa held the first public meeting of a panel established to investigate sightings of UFOs. It came just before a whistleblower former intelligence official told the Debrief that the US government had ‘intact and partially intact’ craft of non-human origin. Ian Sample talks to Prof David Spergel, the independent chair of Nasa’s panel, about why this is happening now, what they hope to find and why there is so much stigma attached to this field. Help support our independent journalism at theguardian.com/sciencepod

Ian Sample talks to Dr Rachel Clarke about her experience working in palliative care in the NHS and now with hospices in Ukraine. She tells him what dying can teach the living, what we can learn from the Covid pandemic, and reveals the anguish and defiance of trying to provide a dignified death in the midst of war. Help support our independent journalism at theguardian.com/sciencepod

Food allergies appear to be increasing globally, but as scientific understanding improves, some experts believe we may one day be able to eliminate them altogether. Ian Sample speaks to Dr Kari Nadeau, an allergy specialist at Harvard School of Public Health and author of the book The End of Food Allergy, to discuss why food allergies are on the rise and what we can do to prevent – and possibly even cure – them. Help support our independent journalism at theguardian.com/sciencepod

Every year, the world’s leaders gather for the UN climate change conference. At Cop28, they will be faced with two stark warnings from scientists: we are likely to breach 1.5C warming above pre-industrial levels in the next five years, and we are on course to reach 2.7C of warming by the end of the century. Progress has never been more critical and this year it lies in the hands of the United Arab Emirates, a country that has plans to expand its already extensive oil and gas productions. With six months to go, Madeleine Finlay talks to environment correspondent Fiona Harvey about Cop28’s hosts and president, why this year is particularly key, and how close we are getting to irreversible climate tipping points. Help support our independent journalism at theguardian.com/sciencepod

Since it was introduced to the UK in 1850, Japanese knotweed has gone from novel ornamental plant to rampant invasive species. Madeleine Finlay speaks to journalist Samanth Subramanian about the huge costs associated with finding it on a property, and Dr Sophie Hocking explains what the plant, and our attempts to control it, might be doing to the environment.. Help support our independent journalism at theguardian.com/sciencepod