大象传媒

Much of the Rio Olympics build-up in the last few weeks has centred around drug abuse. The recent report from World Anti-doping Agency has resulted in 67 Russian athletes being barred, as well as bans for swimming, canoeing, and sailing. Adam Rutherford visits the Drugs Control Lab at Kings College London to meet its director David Cowan. He ran the drugs testing lab at the London Olympics four years ago and discusses how science is addressing new methods to evade detection.

Many scientists think life first emerged not in a primeval soup, but in hydrothermal vents at the bottom of the ocean. But we don't have much of an idea of what that life would have been like. We call it LUCA - the 'last universal common ancestor' - basically the root of all life on Earth. Professor of Biochemistry Bill Martin has used the genomes of living organisms to piece together the first ever profile of LUCA.

Lichens cover gravestones and rocks and trees all over the planet. But they're scientifically fascinating because a lichen is not one organism at all. Lichens have been described as "dual organisms", one an alga and the other a fungus living in symbiotic harmony. But as researcher Toby Spribille reveals, we've been wrong about that for more than a century. Lichen is not one organism, or two, but a very comfortable m茅nage a trois.

Who can forget the joy we all felt when the Rosetta Mission deployed its solar-powered lander Philae onto the surface of the comet 67p in November 2014. Yesterday, the European Space Agency switched off the Electrical Support System Processor Unit on-board the Rosetta orbiter, meaning that communications with the Philae lander are at an end. Project scientist Matt Taylor bids farewell to Philae

Producer Adrian Washbourne.