Astrophysicists at the University of Cambridge have used theoretical models to determine the origins of the striking large-scale spiral features surrounding a nearby star. Young stars are surrounded by dense discs of gas and dust, and it is within these discs that planets are assembled. Obscured from our view, the precise details of just how planets form remain difficult to determine from the observations alone. Last year, astronomers used the extremely sensitive Atacama Large Millimetre Array (ALMA) located in Chile to observe the young, one-million year old star Elias 2-27 (Pérez et al. 2016, Science 353, 1519). The observations were the first to directly resolve the disc around the young star, and showed something very surprising - rather than being a smooth disc, the image showed two prominent spiral arms, each extended to a length about ten times the distance between the Sun and Neptune in our own Solar System. Read more