Airglow

Airglow (also called nightglow) is a faint emission of light by a planetary atmosphere. In the case of Earth's atmosphere, this optical phenomenon causes the night sky never to be completely dark, even after the effects of starlight and diffused sunlight from the far side are removed.

Development

The airglow phenomenon was first identified in 1868 by Swedish scientist Anders Ångström. Since then, it has been studied in the laboratory, and various chemical reactions have been observed to emit electromagnetic energy as part of the process. Scientists have identified some of those processes that would be present in Earth's atmosphere, and astronomers have verified that such emissions are present.

Description

Airglow is caused by various processes in the upper atmosphere, such as the recombination of atoms which were photoionized by the sun during the day, luminescence caused by cosmic rays striking the upper atmosphere, and chemiluminescence caused mainly by oxygen and nitrogen reacting with hydroxyl ions at heights of a few hundred kilometres. It is not noticeable during the daytime because of the scattered light from the sun.

Airglow (aircraft)

Airglow is a human powered aircraft. It was designed and developed by brothers John and Mark McIntyre of Cambridgeshire, England.

Development

John McIntyre holds a marine engineering degree, and Mark McIntyre is a professional model-builder, both brothers were keen aero-modelers and had a history of building creative contraptions including a sail-propelled-bicycle and a hot-air-balloon which carried a camera. Work on Airglow began after John accompanied Daedalus on its epic flight. Airglow was built over a three-year period to exacting standards, any part not perfect was scrapped and re-built. Testament to this is the fact that airglow is one of the lightest HPA ever built, and has had a flying life longer than any other. Airglow took longer to build than was expected, in Johns words “We thought that if Dr Who could build a trans-dimensional flux damper in less than one episode that what we wanted to do would be simple”

Unlike many HPA builders Airglow wasn’t built to break records or win Kremer prizes. Johns states that it was built ‘for delight’ and because ‘it’s fun to make things’.