Researchers from the University of Warwick commissioned this illustration to support their press release about small planets forming via a new mechanism. Observations show that protoplanetary discs - pancakes of gas that surround new stars, inside of which planets are accreting - often have gaps in them, where the material density is lower than average. The research suggests that the gaps are caused by giant planets vacuuming up the gas in their orbit. Meanwhile, in the rings between the gaps, smaller, rocky planets are formed - sandwiched between the two gas giants. 'This is very different to the conventional view of planet formation, ' said Farzana Meru, one of the researchers, 'where planets form sequentially from the inside to the outside of the disc and get more and more massive further out.'