This week, Chris looks at how measuring elements in samples brought back from asteroids could reveal where the Earth's water came from; Stu asks Greg Neely from the University of Sydney about his research into how box jellyfish cause pain, and how that could lead to an antidote; and Claire talks to Elodie Camprasse about scientists speaking about their work in pubs around the country for Pint of Science, pintofscience.com.au