Depending on your position on the globe, Dec. 21 is either the longest or the shortest day of the year. The winter solstice took place at 5:02 a.m. EST today, and will be closely followed by the Great Conjunction, the closest that Jupiter and Saturn will be together in the sky. The conjunction will only be visible, however, for about an hour after sunset local time. This time lapse from GOES West, above, shows the transition of seasons throughout 2020, from June 21 to December 21.
The solstice happens twice a year, alternating between the longest and shortest days of the year depending on your place on the globe. As the Earth rotates on its axis at a 23.5 degree tilt, places above the Arctic Circle and the North Pole experience 24-hour darkness during the December solstice, while the Antarctic Circle and South Pole have 24-hour daylight. Conversely, the North Pole and its surroundings experience 24-hour daylight, and the South Pole total darkness, with the June solstice.
Additionally, this year’s solstice coincides with an rare astrological event: the conjunction of Jupiter and Saturn. Referred to as the “Christmas Star” by some, the two planets will be best viewed soon after sunset, local time, on Dec. 21, but will also be visible for the rest of this week an hour after sunset. The last time this conjunction took place was in 2000, but it was too near the Sun to be easily observed; NPR also adds that “the 2020 great conjunction of Jupiter and Saturn will be the closest since 1623 and the closest observable since 1226!”
This GeoColor enhanced imagery was created by NOAA's partners at the Cooperative Institute for Research in the Atmosphere. The GOES West satellite, also known as GOES-17, provides geostationary satellite coverage of the Western Hemisphere, including the United States, the Pacific Ocean, Alaska and Hawaii. First launched in March 2018, the satellite became fully operational in February 2019.