Eli ([personal profile] eub) wrote2004-04-18 12:28 am

atmospheric optics

All kinds of cool stuff: sundogs, Heiligenschein, reflection and reflected rainbows, nacreous clouds.

Just for one example, you know the repeated purple/green fringes you sometimes see on a rainbow's inner edge? Seems they're an interference effect.


HaloSim software renders Martian CO2-crystal halos:

[identity profile] coyotegirl.livejournal.com 2004-04-20 12:02 pm (UTC)(link)
alas, that site doesn't seem to have information on the kind of rainbow Sean and I saw a few weeks ago...

The sun was setting, and about 30 degrees off of it, on both sides, were very short rainbow arcs (concave sides towards the sun), but with the red on the inside. I have never seen anything like that before. It was most cool.

[identity profile] eub.livejournal.com 2004-04-22 01:15 am (UTC)(link)
Cool! It's tantalizingly like a 22° halo with nearly-aligned crystals. They have the two bright parts above and below, and I guess to get them at the sides like yours, the crystals would need to be randomly pitched, but all in planes aligned towards you. Seems tough to arrange.