November 6, 2012
Noctilucent clouds (or "night-shining clouds") over Mount Tabor Park, Portland, Ore., July 23, 2009. This photo was taken by Mark Seibold, an artist, astronomer and astronomy art lecturer from Portland, Ore. Here's Seibold's first-hand account experiencing these iridescent, nighttime clouds (originally posted on www.spaceweather.com): "I ensconced myself on top of Mount Tabor in central Portland, Ore., to render a pastel sketch of the two-day-old crescent moon, observed through a Nexstar 5i Cassegrain as one of my usual works. As I was showing the public the moon setting onto Portland's West Hills through the telescope, I noticed a strange silver light in what appeared as the north-northwest sky, lighting up with I thought was aurora borealis. I then realized that I was seeing the most amazing display of noctilucent clouds that I had ever witnessed. Perhaps my first ever. I had to drop the pastel chalks, grab the camera and take a vantage point on the slopes of the west of Mount Tabor over the large reservoir, with the city skyline to the west. It was at 10:15 p.m. PDT, an hour and a half after sunset in dark sky with only a hint of twilight glow at the horizon's edge." Credit: Mark Seibold, Artist-Astronomer-Astronomy Art Lecturer, Portland, Ore.
Topics: Volcanism, Noctilucent cloud, Geography of the United States, Portland, Oregon, Mark Seibold, Mount Tabor, Portland, Oregon, Cloud, Geology, Hospitality Recreation