Planet Soup

Despite being the second most abundant element in the universe, helium is found in only trace quantities in the Earth and is too light to be retained by our atmosphere; but is essential in cryogenic applications such as enabling superconducting magnets in medical MRI scanners to work. Helium rich natural gases have only ever been found by accident but now known sources are running out. This talk will take us to the plains of the USA, the Rocky Mountains and the West African Great Rift Valley to show how we can develop an exploration strategy that will find news supplies of helium for society.

Earth formed by accretion of smaller planetary objects. Isotopic ages and dynamic models provided evidence that the Moon formed late - more than 30 million years after the start of the Solar System. This fits with a late Giant Impact between an Earth that was >50% formed and a Mars-sized impactor called "Theia", which added most of the remaining mass. In most simulations, the Moon mainly comes from Theia whereas isotopic compositions provide evidence that most atoms came from Earth.  As such, we do not yet have a consistent model of how the Moon formed.