anart
A Disturbance in the Force
Apparently, the moon halo has shifted (or is shifting) from circular to elliptical - has anyone noticed this in their own view of the full/fullish moon? This was carried on spaceweather.com today:
From: http://spaceweather.com/
ELLIPTICAL MOON HALOS: The moon is waxing full, which means now is the time to be alert for icy moon halos. On April 22nd, Darryl Luscombe of Sointula, British Columbia, saw an unusual specimen. Instead of being circular, as usual, this halo was elliptical:
"I dont think I have ever seen an elliptical halo around the moon before," says Luscombe. "I looked up and just stared for about a minute. Then I raced inside to get my camera. I just managed to photograph it before it disappeared."
Atmospheric optics expert Les Cowley comments on the apparition: "There have been quite a few ellipticals seen in the last few weeks both in Europe and the US. Something strange [is happening] in all our skies!"
"These unusual ice halos are much smaller than the ordinary 22 degree halo encircling the sun or moon," Cowley continues. "In the 22 degree halo the ring is effectively made by light refracting through a 60 degree ice prism. The smaller elliptical halos need much narrower prisms and we think that six sided plate shaped crystals with very shallow pyramidal ends might do the work. The problem is that such crystals are unphysical and computer simulations using them do not predict the halo very well. An alternative is the wedge shaped sections of small snowflake-like crystals. Whatever their cause, they are rare and mysterious!"
From: http://spaceweather.com/
ELLIPTICAL MOON HALOS: The moon is waxing full, which means now is the time to be alert for icy moon halos. On April 22nd, Darryl Luscombe of Sointula, British Columbia, saw an unusual specimen. Instead of being circular, as usual, this halo was elliptical:
"I dont think I have ever seen an elliptical halo around the moon before," says Luscombe. "I looked up and just stared for about a minute. Then I raced inside to get my camera. I just managed to photograph it before it disappeared."
Atmospheric optics expert Les Cowley comments on the apparition: "There have been quite a few ellipticals seen in the last few weeks both in Europe and the US. Something strange [is happening] in all our skies!"
"These unusual ice halos are much smaller than the ordinary 22 degree halo encircling the sun or moon," Cowley continues. "In the 22 degree halo the ring is effectively made by light refracting through a 60 degree ice prism. The smaller elliptical halos need much narrower prisms and we think that six sided plate shaped crystals with very shallow pyramidal ends might do the work. The problem is that such crystals are unphysical and computer simulations using them do not predict the halo very well. An alternative is the wedge shaped sections of small snowflake-like crystals. Whatever their cause, they are rare and mysterious!"
