It's nonetheless a gorgeous rendition of what the view would look like if one were to stand on the shores of the moon's 124-mile-long Loki Patera, a magma-filled lake dotted with islands.

The detected volcanic site spans over 40,000 square miles—more than five times the size of the previous record-holder, Loki Patera. With such immense scale, the eruption likely reshaped Io’s ...