Astronaut twins, a Human-Pig Chimera and the Science of Torture

Plus ancient cave drawings, metallic hydrogen and more.
Expedition 45/46 Commander, Astronaut Scott Kelly along with his brother, former Astronaut Mark Kelly speak to news media outlets about Scott Kelly's 1-year mission aboard the International Space Station. January 19, 2015. (NASA/Robert Markowitz)
Listen to the full episode54:00

Plus ancient cave engravings, metallic hydrogen and more.