The Earth has just received another dazzling glamor shot, thanks to a satellite that shot its photo on the spring of spring of March 20th. This photo shows half of the planet illuminated by light and the other is bathed in darkness like a black and white biscuit.
This beautiful symmetry is no surprise for those who are familiar with the daytime. Equinox means "same night" in Latin. Twice a year, in March and September, the equinoxes take place when daylight and darkness are almost the same in all latitudes, according to the National Oceanic and Atmospheric Administration (NOAA).
Why are equinoxes not common? The answer has to do with the tilt of the earth. Since the planet is tilted about its axis by 23.5 degrees, the daylight is usually distributed unevenly over the planet. Depending on where the Earth is in orbit around the Sun, the Northern Hemisphere or the Southern Hemisphere will have longer days or nights. [Earth Pictures: Iconic Images of Earth from Space]
"At two special times twice a year, the slope is actually perpendicular to the sun, which means that the Earth is equally illuminated in the northern and southern hemispheres," said C. Alex Young, associate director of science in the NASA's Heliophysics Science Division Goddard Space Flight Center, previously told Live Science.
In other words, during an equinox, the sun is at noon right above the equator.
Last week, the equinox was held at 5:58 pm. EDT on Wednesday (March 20), the first astronomical spring day of the Northern Hemisphere. However, the new image was taken a few hours earlier at 8:00 am EDT from the GOES EAST satellite.
GOES satellites, also referred to as geostationary environmental satellite systems, are a network of earth observation satellites operated by the NOAA. They collect information on weather forecasts, severe storm tracking and meteorology research.
Originally) released on Live Science,