The first of four full supermoons this year has lit up the night skies around the world.In some places, the supermoon – also a blue moon – turned red due to smoke from wildfires in North America. Smoke particles mean that light passing through the atmosphere is scattered in such a way that the orange and red colours of the spectrum are more visible than usual.Blue moons are not that common – it’s thought this is where the phrase “once in a blue moon” comes from.The full moons of September, October – the closest moon this year – and November will also be supermoons.