The ‘bright night’ phenomenon is fascinating and mysterious for most of us. Even scientists were puzzled and they had worked hard to know the mystery behind this. Finally, they have got the answer and reason behind the occurrence of the bright night.
As per the study, the upper atmosphere waves converge over the specific place on the earth and amplify the airglow. The slow moving waves at high altitude merge together and enlarge the naturally occurring airglow. Due to the activities of atoms of oxygen in the upper environment, the airglow sometimes appears green. Emissions from various colors of light from chemical reactions are responsible for the airglow. When the light from sun splits apart into individual oxygen atoms, it produces green colored airglow.
Most of the times, we do not notice this airglow event. Do not panic, if you have never seen these bright nights as these are the very rare events. Bright nights are very visible. Even sometimes observers can see distant stars, can look at their watch and can read the newspaper.
This event is very old and people are puzzled from centuries. Even European newspapers and some journals have carried out these observations back in 1783, 1908 and 1916.
Gordon Shepherd, from Canada University, said that bright night does exist. This is a part of the variability of airglow which can be easily detected by satellites instruments.
He further adds that the historical data is very coherent and if we look back over centuries the reports are very similar. The bright night could last for many nights and can create 10 times brighter light than the normal.
The research team further adds that based on historical data the bright night event occurs once in a year. Data suggest that 7 bright nights occur every 100 nights somewhere on the earth.