 On Venus, coronae are large (typically several hundred kilometres across), crown-like, volcanic features.Coronae were first identified in 1983, when the radar imaging equipment aboard the Venera 15 and Venera 16 spacecraft produced higher-resolution images of some features previously thought to be impact craters.It is believed that coronae are formed when plumes of rising hot material in the mantle push the crust upwards into a dome shape, which then collapses in the centre as the molten magma cools and leaks out at the sides, leaving a crown-like structure