http://antwrp.gsfc.nasa.gov/apod/ap000515.html

a single refraction in the ice crystals give a ring at an angle of 22 degress.
Higher levels of refractions in
multiples of 22 and at lower intensity.

Wolfgang wrote:

Standing out on the front stoop just now, I looked up at the full moon. I
was facing nearly due east. High thin clouds looked very much like the
ripples in the sand in the shallows of a lake. Something, presumably ice
crystals, between the observer on the ground and the clouds was refracting
the sunlight reflected off the moon. There was a bright white nimbus
surrounding the moon and extending about two apparent diameters of the moon
all around it. Outside this glowing patch was a ring of barely perceptible
red.....as near infrared as my eyes could detect. Outside that followed all
the colors of the spectrum; sort of a rainbow in the round. Outside that
was another complete rainbow and, outside that, a third. Barely visible in
the white patch were much smaller ripples than those formed by the high
clouds, traveling west to east.

It looked a lot prettier than it probably sounds.

There's a lot of really cool **** in this world......better than T.V. for
the most part.

Wolfgang

--

Svend

************************************************** ***************
Svend Tang-Petersen, MSc Email: svend AT sgi.com
SGI Pager: svend_p AT pager.sgi.com
1500 Crittenden Lane Phone: (+1) 650 933 3618
Mountain View
California 94043
USA
MS 30-2-526
************************************************** ***************