Monday, 5 March 2018

Odd radius plate display from the Czech Republic

On 4th March Jitka R. from the Czech republic captured this magnificent odd radius display on the Moon. After stacking multiple images, many halo forms showed up - particulary 9°, 18°, 20°, 24° and 35° halos, along with 9° and 24° plate arcs.

It was a case of sublimating cirrus, which could be easily seen on the satellite images.

And I have a question for the halo experts - is it possible that the 9° column arcs are captured, too? Or could it just be a cirrus of a higher quality?


  1. That is a beautiful odd radius display

  2. Possibly the 9° halo enhancements are a sign of poor column orientations. But you might want to get a better defined case before you tick the 9° column arc. Well, I guess it is up to anyone's preferences.

    1. Thank you Marko for your insights on this. I thought so the same. Of course it would be nice to tick the box, but I think by being "reckless" for the lack of a better word, then this would probably not be the first case of 9° plate arcs in the Czech Republic.

  3. Yeah, especially if it is going to be the first one in the Czech Republic, then you might like it to be a robust case, a source of pride. Purists and connoisseurs may prefer to accept only cases where the column arcs exhibit their true arc shape separating from 9° halo, but then our column arc observations would hopelessly few and far between.