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.

And All living things are related to each other, from elephants to algae, e-coli to humans like us. Within our cells we hold genetic information in the form of DNA or RNA. But despite viruses sharing these molecules, many scientists don't consider them to be 'life'. Viruses cannot reproduce on their own, but some can insert their DNA into a host to pass genes sideways through the branching tree of life. As a result, viruses’ relationship with life is.... complex.

Two of our listeners had viruses on the mind, so they sent in the same question to CrowdScience. Senan from Singapore and Melvin from South Africa want to know how viruses began to see if this can tell us whether they shared a common ancestor with humans.

To dig into this complexity Marnie Chesterton speaks with an expert on Koala genetics – Dr Rachael Tarlinton. Koalas are in the middle of tackling a retroviruses, a type of virus that plants DNA into our cells as a reproduction strategy. Her research could reveal why humans life has so much viral DNA within our genomes.

Marnie speaks with a computational biologist Professor Gustavo Caetano-Anolles, who has found a new way to trace the family tree for billions of years using proteins common to all life on earth, and speaks with Professor Chantal Abergel who paints a picture of how viruses went from being the losers of evolution, to being highly successful parasites of cells.

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