There are several names for this type of photography including Landscape Astrophotography, Wide Field Astrophotography, and Nightscapes. It's a type of astrophotography that combines night landscapes with wide field astrophotography. This has only become practical within the last 6-8 years as camera sensor technology advanced. I became interested in this field after seeing a few early landscape astrophotography photos on the internet 5-6 years ago. The next year I had the chance to try capturing a few Milky Way images along the North Rim of the Grand Canyon. I was immediately hooked when the first image appeared on my camera LCD screen. For me, there was no looking back.
These photos require very dark skies, and were taken in some of the darkest places in this country, and in the world. The eastern half of the USA, most of Europe, and parts of Asia have too much light pollution to perform this kind of photography. The camera captures a lot of subtle color in the night sky that we cannot see with our eyes. The green is primarily airglow, appearing somewhat like the aurora. The sun’s extreme ultraviolet light excites oxygen and nitrogen atoms in the upper atmosphere during the day. The resulting products then interact with other atmospheric components to later produce light emission by chemical luminescence at night. This is called airglow and is most often green or red. The camera captures these colors but we see only a faint grey illumination with our eyes. The yellow and orange tones are frequently are due to light pollution but can also be due to the setting or rising sun or moon. Light pollution from a city can be seen for hundreds of miles. The stars themselves have different colors and there is a lot of subtle color in the core of the Milky Way. In many of these photos the nearby landscape is illuminated to some degree using a technique called Low Level Lighting (http://www.lowlevellighting.org).