2011 Noctilucent Cloud Sightings2011 Noctilucent Cloud Sightings
Noctilucent Clouds <p>The 2011 <a href="https://www.nightskyobserver.com/earth/noctilucent-clouds-in-2009/">noctilucent cloud</a> (NLC) season has begun. For the past few nights, observers in northern parts of Europe have spotted velvety, electric-blue tendrils rippling across the sunset