Red Sky at Night

Clouds may not be an astronomer’s best friend, but they are often a welcome sight for photographers in the rare moments when they grace the desert skies! This unusual scene shows a fiery sky above ESO’s Paranal Observatory in the dry Atacama Desert in Chile, home to the Very Large Telescope (VLT). The VLT comprises four Unit Telescopes, which are larger and squarer, and four smaller and rounder Auxiliary Telescopes, three of which can be seen here sitting quietly, their domes closed, towards the right of the frame.

The cloud is not the only atmospheric phenomenon visible here. On the left of the image, a bright shaft of light can be seen shooting upwards, creating an illuminated column. This is a sun pillar, and is caused by tiny particles of ice within the atmosphere that reflect ambient light. These columns usually appear just above or below a bright source of light — in this case the setting Sun is the source — sending a beam upwards into the evening sky.