By Tyler Wright
If you spotted a large ring around the moon on the night of Sunday 4 June, it was because a lunar 22 degree halo had formed in the sky.
Photographer Nicole Bates captured the phenomenon from The Basin, posting the image to social media.
“[It] got brighter as the night went on,” Ms Bates wrote.
The images prompted comments from Facebook users including Janice Dean.
“Brilliant pic Nicole,” Ms Dean wrote.
“Nicole. Spectacular!,” Janette Greenall from Olinda added.
Mount Burnett Observatory committee member Jacquie Milner said the lunar halo us formed by ice crystals from cirrus clouds bending the light towards earth in a 22 degree halo.
“You can get them with the sun and the moon…we don’t tend to see them in the day time because we’re conditioned not to look at the sun,” Ms Milner said.
“That’s the easiest part of a big complex part of a set of atmospheric optics that ice crystals form. We usually don’t see the rest of the set because it’s not cold enough.
“Different shaped ice crystals form and you get things like sun dogs and much bigger secondary rings as well, but you tend to only see them in latitudes which are closer to the poles.”
Because lunar halos are not seen as often in Australia as they are in other countries, Ms Milner said, people tend to think of them as a “weird” occurrence.
“Usually people will see them and say ‘oh, the weather is coming, or it’s going to rain in a couple of days’; and that’s because you often get serious cloud being blown off the top of cold fronts and so they’re heralding the cold front coming through,” Ms Milner said.
“Sometimes you just get a high pressure system and there’s a bit of random cirrus cloud around or light cloud haze over the sun and it will cause that effect as well.”
Ms Milner said while the halo is “pretty to see,” it is not startling and quite common.
“Enjoy the prettiness, but certainly don’t be startled with it,” she said.
“It’s quite a natural phenomenon, and it occurs all the time.
“Often the moon causes moon bows, but they’re not seen as often as rainbows.”
