Astronomers prepare for December's Cold Moon
Astronomers across the world are preparing for December’s Cold Moon on Saturday, the last full moon of 2018.
The exact time when the moon comes opposite the sun is 17.48, though witnesses will be able to see the full moon at any point overnight.
“It will be visible throughout the night, for anyone who has clear skies – the actual moment of the full moon, the point where the moon comes exactly opposite the sun in the sky will be at 17.48, so just coming up to six o’clock, but there will be no appreciable difference in how the moon appears,” said Tom Kerss, an astronomer at Royal Observatory Greenwich.
“As it stands, it’s looking rather cloudy, not completely overcast here in the South so there might be quite a lot of cloud, but if the cloud is thin cloud, then the moon is very dramatic anyway, being so bright in the sky thin cloud normally isn’t enough to stop the moon light coming through – and if you have a telescope or something like that you can usually see the details on the surface of the moon, even through a small amount of thin cloud.”
The astronomer warned that the moon may appear bigger but said this is just an illusion.
“You will notice as well that when the moon is rising and setting when it’s a full moon in particular it has a tendency to look very large and this is an illusion created by our brains when things are close to the horizon,” he explained.
“But also something that is not an illusion is that the rising and setting can take on quite a warm colour, sort of a yellow, orange tone and this is because moon light, which is sunlight bouncing off the moon, is being filtered through our atmosphere, so in the same way that sunsets look red, moon sets and moon rises also have a slightly reddish colour to them.”
Though there aren’t any noticeable differences in a full moon, the event does take place during the Ursids meteor shower, which could provide some extra special lunar photography.
The event is particularly notable this year as it occurs around the 50th anniversary of Apollo 8, the first time humans could see the whole of the planet at once.