Add articles to your saved list and come back to them any time.<\/p>\n
Winter will conclude with an astronomical double act on Wednesday and Thursday as a rare blue supermoon illuminates the night sky.<\/p>\n
For the first time since 2009, a supermoon and a blue moon will coincide. The full moon rising on Wednesday is the second supermoon this month, and it\u2019ll appear bigger and brighter than normal.<\/p>\n
<\/p>\n
The moon in Sydney, one day after clouds obscured a supermoon in November 2016. <\/span>Credit: <\/span> Janie Barrett.<\/cite><\/p>\n The peak of the blue supermoon will occur on Wednesday night, but the phenomenon will still be unfolding on Thursday night as well.<\/p>\n Keen observers should keep their eyes on the horizon just after sunset to experience the full effect of the moon looking larger, Professor of Astrophysics at Macquarie University Richard de Grijs said.<\/p>\n \u201cThere are trees and buildings and all that, so you have a scale to compare the moon with if it\u2019s close to the horizon,\u201d de Grijs said. \u201cIf it\u2019s up higher in the sky, you\u2019ve got nothing to compare it with.<\/p>\n \u201cSecondly, when it\u2019s close to the horizon, the light reflecting off the moon coming towards you is refracted by the atmosphere. Because of that refraction, the moon starts to look a little bit bigger than it actually is.\u201d<\/p>\n A supermoon occurs when a full moon swells at the same time the moon is at its closest point to Earth.<\/p>\n The moon doesn\u2019t have a perfectly circular orbit. Its path around our planet is more of an ellipse, or oval, meaning that sometimes the moon is physically further away from Earth and sometimes it\u2019s closer.<\/p>\n A super blood moon rises off Sydney\u2019s Manly Beach in 2018.<\/span>Credit: <\/span>Getty<\/cite><\/p>\n At its furthest distance from Earth, the moon swings to a distance of 405,500 kilometres, a point known as the apogee. The moon\u2019s closest point to Earth is the perigee, about 363,300 kilometres from Earth, or about 42,000 kilometres closer than the apogee.<\/p>\n When a full moon coincides with the moon arriving at the perigee, it\u2019s known as a supermoon.<\/p>\n A full moon at the perigee is 14 per cent closer and 30 per cent brighter than a full moon farthest from Earth, or micromoon.<\/p>\n There are about three or four supermoons in a normal year; this month\u2019s will be the closest and brightest supermoon.<\/p>\n The term supermoon came from the less than scientific realm of astrology, not astronomy. If zodiac signs aren\u2019t your thing, you can use the supermoon\u2019s technical name: the perigee syzygy.<\/p>\n The blue moon might be most notorious for the famous phrase used to describe an infrequent event.<\/p>\n But it\u2019s also a colloquial term used when two full moons rise during the same month; the second full moon in a calendar month is called the blue moon. Professor de Grijs explains they come around once every two or three years because the lunar cycle is 29.5 days.<\/p>\nWhen is the best time to see the blue supermoon in Australia?<\/h3>\n
What\u2019s a supermoon?<\/h3>\n
<\/p>\n
What\u2019s a blue moon?<\/strong><\/h3>\n
<\/p>\n