The Press Stories
Earth is a genuinely magical position.
We know that’s not the form of thing you would count on to browse on a science web page, but just get a seem at the picture previously mentioned – a pre-dawn photo taken by an Expedition 62 crew member on the International Place Station (ISS) back in March.
In this picture, taken when the ISS was traveling just south of the Alaskan Peninsula, the amazing colors you’re observing are particles in Earth’s upper environment interacting in diverse methods, resulting in two completely various atmospheric phenomena in 1 photo.
Truly magical to glimpse at, but also easily explained with some science.
The very first phenomenon is the aurora – the glowing inexperienced, crimson-tipped phenomenon on the still left side of the image. Auroras occur when charged particles from the solar wind hit Earth’s magnetosphere – a type of protective cloak wherever these particles are at the whims of our magnetic area.
https://www.youtube.com/enjoy?v=IC-UPAzrMzM
Mixed with atmospheric gases this kind of as oxygen and nitrogen, the particles create the colours we know as the aurora.
Excited by photo voltaic wind, oxygen atoms at the best altitude launch this extra electrical power as the purple glow, while the eco-friendly is brought on by excited oxygen or nitrogen molecules releasing strength at reduce altitudes.
But the aurora is only one part of this certain shot. Shifting appropriate on the picture earlier mentioned, acquire a appear at the yellow-purple band of gentle proper above the curve of our earth. It’s known as an ‘airglow’, and it is much more subtle than the aurora, but just as neat.
To have an understanding of airglow – much more exclusively nightglow – you require to bear in mind that the night sky is never ever absolutely darkish, not even at the time you’ve extracted gentle air pollution, starlight, and diffuse sunlight.
Alternatively, atoms create ’emissions’ from getting in their enthusiastic condition. For instance, oxygen which is been broken apart all through the working day recombine and release their added strength as photons at night. Nitrogen molecules and reactions between nitrogen and oxygen contribute to this glow as nicely.
Earth’s nightglow. (NASA)
The photons released in this circumstance surface green, as in this impression higher than, but yellow often happens at a reduce layer (all-around 80 to 100 kilometres over the surface area of Earth).
Meteors break up in this layer of the environment, and launch sodium atoms into the air, that’s why it really is aptly named the sodium layer enthusiastic sodium atoms will build a distinctly yellow glow.
As a bonus, the mounting sunshine guiding Earth is causing the edge of the planet to appear dark blue. This takes place for the identical rationale that the sky is blue through the working day – when daylight hits the molecules in our ambiance, blue gentle (1 of the shortest wavelengths) is scattered, whilst other colored light is primarily permit by.
We informed you, completely magical.
