halo around the moon

[fairway68]

A beautiful sight on night of 18th through the seemingly ever present cloud, was the speccy halo ( corona?) around the moon. How does this happen? It looks like diffraction.. Any clues?

PS. Location; lower east coast,NSW

Peter.

[okiscopey (Mike)]

If the halo was colourless and 22 degrees in radius (approx. thumb-tip to little finger tip with hand held at arm's length) then it was probably an ice halo caused by refraction and reflection from tiny atmospheric ice crystals.

If coloured, then it was a 'corona' caused by diffraction or scattering by cloud water droplets.

I'm not an expert though! I got this from:

http://www.atoptics.co.uk/droplets/cormoon.htm

and

http://www.atoptics.co.uk/halo/circmoon.htm

Fascinating stuff!

[madtuna (Steve)]

Hi Peter!
Here's a good thread with some nice captures by Matty P of the same halo you saw.

http://www.iceinspace.com.au/forum/s...highlight=halo

[renormalised (Carl)]

Most of the halos I've seen around the Moon lately have been coronas. They're too small to be proper ice halos and they exhibit a spread spectrum (rainbow effect), anyway.

A nice, strong ice halo is pretty spectacular to see

[Jen]

yes i looked great