Sunday, July 30, 2017

PHOTOGRAPH - Aurora Slathers up the Sky

Aurora Slathers up the Sky:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2017 July 29



See Explanation. Clicking on the picture will download the highest resolution version available.


Aurora Slathers up the Sky

Image Credit: Jack Fischer, Expedition 52, NASA


Explanation: Like salsa verde on your favorite burrito, a green aurora slathers up the sky in this June 25 snapshot from the International Space Station. About 400 kilometers (250 miles) above Earth, the orbiting station is itself within the upper realm of the auroral displays. Aurorae have the signature colors of excited molecules and atoms at the low densities found at extreme altitudes. Emission from atomic oxygen dominates this view. The tantalizing glow is green at lower altitudes, but rarer reddish bands extend above the space station's horizon. The orbital scene was captured while passing over a point south and east of Australia, with stars above the horizon at the right belonging to the constellation Canis Major, Orion's big dog. Sirius, alpha star of Canis Major, is the brightest star near the Earth's limb.

Tomorrow's picture: end of the world



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