Noctilucent Clouds Above Base Marambio, Antarctica

April 16, 2018

Antarctic_noctilucent_nubesnoctilucentes (1)

Photographer: Jorgelina Alvarez 
Summary Authors: Jorgelina Alvarez; Jim Foster

Featured above are noctilucent clouds as viewed from Base Marambio (Argentina) in Antarctica. In mid-February here, while the Sun is no longer above the horizon, it's not far from it. Thus, atmospheric twilight phenomena can be observed when conditions are favorable, including these bright, high altitude clouds. We were pleasantly surprised one evening when we ventured out to stargaze.

Noctilucent clouds form in the atmospheric layer known as the mesosphere, approximately 55 mi (88 km) above the Earth's surface. When meteors enter the Earth's upper atmosphere, where there's very little atmospheric pressure, they leave behind a small dust trail. Minute ice crystals adhering to the dust particles glow from the sunlight still reaching the mesosphere, resulting in the whitish, sometimes electric blue clouds. Photo taken on February 18, 2018, at 11:30 p.m.

Photo Details: 8 images - Cs6- Sony A7s camera; ISO 2500; f2.8; processed in Photoshop.