Quartz sand is anywhere and everywhere imaginable on the surface of the Earth. It forms the vast sandy Sahara and Arabian deserts, where dunes can reach a staggering 180 meters (600 ft) in height. It makes up the world's immense sandstone deposits, forms our beaches and is present in most soils around the globe. The question is: where did all the sand come from? All scholars hold the view that the primary source of our sand lies with the weathering and erosion of granite outcrops - a process that is said to take billions of years (uniformitarianism). But is this correct? Is there anybody brave enough to challenge this seemingly impregnable bastion of geological principles? Extraterrestrial Sands does just that. Extraterrestrial Sands dismantles the consensus model and explores the radical idea that sand is extraterrestrial in origin. The theory states that the planet Mars entered into hundreds of catastrophic close encounters with earth during historical times. During these encounters an incandescent molten Mars internally convulsed and ejected immeasurable quantities of vaporised rock, volatiles, dust and debris out into space - a natural by-product of planetary chaos. Vast swaths of rock vapour fell to earth (along with tons of other sedimentary material) where it condensed out of the atmosphere as tiny quartz grains. In other words, it rained sand! Earth has been subjected to a number of catastrophic sand and debris 'accretion events' in the past few thousand years and the evidence is obvious for all to see. It reaches us in the form of Earth's sandy deserts, beaches, dune fields and sandstone deposits. If proven, the theory laid out in Extraterrestrial Sands has the potential to rewrite Earth's history. A fascinating read, it will appeal to those with an interest in global and Martian geology.