December Solstice

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We had seven hours of daylight today. The Sun came up at five minutes to nine o’clock this morning, and set at eight minutes after four in the afternoon. Today the North Pole is tilted furthest from the sun. This tilt of the Earth gives us shorter days in the Northern Hemisphere. We receive less energy from the sun because we face away from the sun and our days are shorter.

In celebration of the sun, here is an image from NASA’s Solar Dynamics Observatory:

image of the sun highlighting coronal loops and magnetic fields
A view of our sun today, channel AIA 171. Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.

 

The photo was taken on a wavelength band or channel called AIA 171. This channel is especially good at showing coronal loops – the arcs extending off of the Sun where plasma moves along magnetic field lines. The brightest spots seen here are locations where the magnetic field near the surface is exceptionally strong.
Where: Quiet corona and upper transition region
Wavelength: 171 angstroms (0.0000000171 m) = Extreme Ultraviolet
Primary ions seen: 8 times ionized iron (Fe IX)
Characteristic temperature: 1 million K (1.8 million F)

Solar Dynamics Observatory

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