Noctilucent clouds season is not going to end

Syktyvkar, Russia, July 17, 2013 © Pavel S |

July 20, 2013. Owing to the change of astronomical and atmospheric factors season of noctilucent clouds is nearing completion. Still glowing gossamer thin continues to delight his fans in different parts of the Northern Hemisphere.

At night, July 14 in the twilight of the Moscow sky once again appeared gently glowing clouds. Even those who previously had never seen such a phenomenon, immediately realized that this silver cloud.

Indeed, with silver clouds is difficult to make a mistake. Either they have it or not. Other — tropospheric clouds — look dark spots, as are lower and not covered by solar rays. A silver cloud is at an altitude of about 80 km, located illuminated from below the horizon the sun and therefore have a unique silvery glow.

In the long-term average of noctilucent clouds season ends on July 10. But the nature of the hard drive into the rigid framework of the calendar. So observers should still be alert.

The clouds may appear in 30-60 minutes after sunset, when the light falls on 6-16 ° below the horizon. If you see a segment in the twilight sky glowing wavy lines, antennae, ripples or scallops, you immediately realize that this is — noctilucent clouds!

Lithuania, July 18, 2013 © Tadas Janusonis |

Boeing 787, the height of 13,000 meters on the route from Denver to the Aleutian Islands, July 15, 2013 © Tim Trepetch |

Source: News Gismeteo

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