From the ground, a green aurora can look like a curtain stretched across the sky. From the International Space Station, it becomes a luminous band around the planet. Put the two viewpoints together and a familiar northern-lights photograph starts to tell a much bigger story.
Photo: Nasa.gov
This selection brings together archive images from Earth’s surface and orbit. The original collection was assembled around St Patrick’s Day, but the colour has an atmospheric explanation that is interesting in every season.
Why so much green?
As NASA explains, energetic particles interacting with gases high in the atmosphere produce auroral light. Oxygen contributes green and red emissions, while nitrogen contributes other colours. The display is occurring in the atmosphere; it is not coloured sunlight reflecting from snow.
Photo: NASA/Zoltan Kenwell
The names refer to hemisphere: aurora borealis in the north and aurora australis in the south. An image taken from orbit should not automatically be called northern lights simply because it shows green aurora.
Change the viewpoint, change the story
Photo: ESA/Alexander Gerst
Photo: NASA Goddard on Flickr
The space-station photographs emphasise the curve of Earth and the extent of the luminous band. Ground-level photographs use trees, mountains and water to make the sky feel connected to a recognisable place.
Compare the reflection image with the orbital one. Both use a boundary to organise the scene, but one boundary is a lake shore and the other is the planet’s horizon. That is a lovely example of a compositional idea working at very different scales.
Photo: United States Air Force
A photograph’s brightness and colour also depend on exposure and processing. It should not be treated as a guarantee of what every observer saw with the unaided eye.
For aurora photographed closer to real-time motion, explore Harald Albrigtsen’s whales and northern lights. For another orbital perspective, see ISS Symphony.
Two viewpoints on the same luminous atmosphere
Start with a ground photograph, then move to a station image and look for the horizon in each. A mountain or line of trees divides earth from sky at a familiar scale; the curved planetary edge gives the orbital picture a very different frame of reference. The comparison helps explain why the same atmospheric phenomenon can appear like a curtain in one image and a band in another. The photographers’ dates and locations then bring each view back to a specific observation.
The original selection also records dates and photographers, including Jónína Óskarsdóttir in Iceland, Peter Rosén in Sweden and astronauts Samantha Cristoforetti, Alexander Gerst and Terry Virts. The dates and locations reveal how similar green displays appear in different settings, from ground-level landscapes to an orbital view. Green links the selection to its St Patrick's Day theme: the images span several years and were not all taken on 17 March.
Sources, photography and further reading
Original feature and image attributions:
- Saint Patrick’s Day
- aurora
- Nasa.gov
- NASA
- ESA/Samantha Cristoforetti
- NASA/Zoltan Kenwell
- NASA/JSC
- NASA
- NASA/Christopher Perry
- NASA
- ESA/Alexander Gerst
- Peter Rosén
- Nasa.gov
- NASA
- NASA
- Nasa.gov
- NASA/Terry Virts
- NASA Goddard on Flickr
- NASA/JSC
- United States Air Force
- Twisted Sifter
- The Northern Lights in Real-Time, Ultra HD
- This is What Aurora Borealis Looks Like in Real-Time
- This Stunning Time-Lapse Video Captures The Amazing Beauty Of The Northern Lights. Spectacular!
- Dazzling Displays of Aurora Borealis Dance Across the Night Sky
- The Best 10 Places to See The Magnificent Northern Lights!
- NASA explains
- NASA
- David Cartier Sr., via NASA Goddard
- Harald Albrigtsen’s whales and northern lights
- ISS Symphony
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