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NASA's Suomi NPP satellite spotted an aurora snaking across northern Canada. Photo by NASA/Earth Observatory/Suomi NPP/VIIRS |
By Brooks Hays, UPI
On Tuesday, NASA's Earth Observatory shared an image of the aurora borealis, or northern lights, captured by the Suomi NPP satellite's VIIRS instrument.
The Visible Infrared Imaging Radiometer Suite's day-night band, or DNB sensor, is designed to observe a range of wavelengths from green to near-infrared. The instrument and the satellite's software uses filtering techniques to isolate different sources of low light, including auroras, wildfires, city lights and even reflected moonlight.
Over the weekend, VIIRS picked up the glow of the northern lights. The aurora was spotted swirling across northern Canada.
When enough high-energy particles from the sun collide with Earth's magnetosphere, some of the particles already trapped in the magnetosphere get knocked into the upper atmosphere. As these particles hit oxygen and nitrogen gas, they cause the molecules to vibrate and glow a variety of bright colors.
Unfortunately, Suomi's VIIRS images don't render its low-light targets in color. However, the impressive revolution of the satellite's images can help scientists understand the dynamics of complex phenomena like auroras.
"When I first saw images like this as a graduate student, I was immediately struck by the fluid dynamic characteristics of the aurora," Tom Moore, a space physicist at NASA's Goddard Space Flight Center, said in a blog post describing the unique imaging abilities of the Visible Infrared Imaging Radiometer Suite.
"Viewing the aurora in this way makes it immediately clear that space weather is an interaction of fluids from the Sun with those of the Earth's upper atmosphere," Moore said. "The electrodynamics make for important differences between plasmas and ordinary fluids, but familiar behaviors (for example, waves and vortices) are still very apparent. It makes me wonder at the ability of apparently empty space to behave like a fluid."
The blast of solar particles that triggered the photographed aurora were expelled by the sun on April 19 and hit Earth's magnetosphere on April 21.
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