Nasa's Perseverance Rover has found a fascinating rock on Mars that may indicate it hosted microbial life billions of years ago. Abigail Allwood, exobiologist at Nasa’s Jet Propulsion Lab, is on the team scrutinising the new Martian data.

And a couple of newly discovered, approximately 500 year old fossils from the ‘Cambrian explosion’ of complexity caught presenter Roland Pease’s eye this week. First Martin Smith from Durham University tells us about a tiny grub that is ancestor to worms, insects, spiders and crustaceans. Then Ma Xiaoya, who has positions at both Yunnan University in China and Exeter University in the UK, tells us about a spiny slug that was also discovered in a famous fossil site in China.

And the first sightings of the landscapes on the underside of the ice shelves that fringe Antarctica. These float atop the ocean around the frozen continent but effectively hold back the glaciers and ice sheets on the vast landmass. Their physical condition therefore is pretty critical in this warming world, Anna Wåhlin of Gothenburg University tells us.

Presenter: Roland Pease
Producer: Jonathan Blackwell
Production co-ordinator: Jana Bennett-Holesworth

(Photo: Nasa’s Perseverance Mars rover taking a selfie on Mars. Credit: Nasa/JPL-Caltech/MSSS)