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Stunning satellite photo shows what the vernal equinox looked like from 22,300 miles away

By John Roach, AccuWeather staff writer
March 21, 2019, 6:02:56 PM EDT

Vernal equinox satellite photo

This geostationary operational environmental satellite image (GOES) East image was captured on March 20, 2019, at 8 a.m. ET prior to the equinox. (Photo courtesy NOAA National Environmental Satellite, Data, and Information Service (NESDIS))

One picture makes it easy to define an equinox: it’s when the Earth is as different as night and day. The National Oceanic and Atmospheric Administration (NOAA) captured the the glory of that fleeting moment on Wednesday in a photo taken by one of its Geostationary and Polar-Orbiting Weather Satellites. The GOES-16, as it's known, is positioned approximately 22,300 miles away from Earth and is lined up at 75.2 W longitude and the equator. The distance is far enough away to provide the breathtaking "full-disk" imagery of our planet.

Twice each year, during a vernal and autumnal equinox, the sun is directly above the Earth’s equator during its orbit, which means the amount of daylight and darkness is almost exactly equal at all latitudes. The photo taken by the GOES-16 on Wednesday, the first day of spring, illustrates this celestial phenomenon in dramatic fashion.

“When the Earth is halfway between the two sides of the orbital plane, things line up perpendicular, but this doesn't last long, as the Earth never stops its orbit," said AccuWeather Senior Meteorologist and Astronomy Blogger Dave Samuhel.

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The perfectly vertical line dividing the darkness and light visible in the above image is a result of the the earth's axis pointing neither toward nor away from the sun -- an occurrence that is short-lived. According to the National Weather Service, “The ‘nearly’ equal hours of day and night is due to refraction of sunlight, or a bending of the light's rays that causes the sun to appear above the horizon when the actual position of the sun is below the horizon." At other times, the dividing line would slant diagonally, with more hours of light in the northern hemisphere until the autumnal equinox and fewer hours of light afterwards.

Meanwhile, spring is underway now -- but that doesn't mean winter's wrath will stop immediately. A major storm system is marching up the East Coast of the U.S., that has the potential to become another 'bomb cyclone' and will bring drenching rains and snow to parts of the Northeast, followed by strong winds. That shouldn't be surprising because the vernal equinox is notorious for bringing winter weather along with the arrival of a new season.

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