Science in Action talks to Nasa researcher Hannah Kaplan who is part of the team for the space agency’s sampling mission to the asteroid Bennu. Mission scientists were overjoyed this week when the probe Osiris Rex momentarily touched the asteroid and sucked up some of the sand and grit on its surface. What might we learn when the sample is returned to Earth in three years' time? There is some not-such-good news about a theory about immunity to the pandemic coronavirus, and medical researchers in the UK announce the world’s first study that will deliberately infect volunteers with the novel coronavirus. The so-called challenge study is planned to begin in London in January. The purpose is to speed up the quest for effective Covid-19 vaccines but will it be safe for the participants? And there’s a new green chemistry breakthrough for tackling the world’s plastic waste crisis.

Presenter: Roland Pease

(Image: Nasa probe Osiris Rex lands on asteroid. Credit Nasa)