The Royal Observatory Greenwich has been working with the New Crescent Society to develop a programme to engage people who use a lunar calendar in their daily lives with the science of the Moon. Our Astronomy and Islam Mornings are held before the predicted sighting of the next new crescent Moon and consist of a monthly planetarium show followed by a practical demonstration to learn how to sight the new crescent. The planetarium shows cover a variety of topics, from the science behind the new crescent visibility, discoveries by key scientific figures from the past, differences in constellations and historical instruments built for navigation and prayer.