Welcome to the official start of astronomical wintermarked by the winter solstice.
In 2024, the winter solstice in the Northern Hemisphere begins December 21 around 4:20 a.m. EST. Although this time it won't be as dramatic as 2020 conjunction of Jupiter and SaturnThe longest night of the year remains a significant turning point. In the future, days (meaning daylight hours) will gradually become longer again.
Curious why this happens? WIRED spoke with Tansu Daylanformer postdoctoral associate of the Transiting Exoplanet Survey Satellite (TESS) at MIT, to better understand the winter solstice and our planet's relationship with the sun.
To visualize what's happening in space at the winter solstice, start by thinking of a giant glass sphere surrounding the Earth and ignore the planet's rotation (which complicates everything). rank). “If you look at the three-dimensional sphere around us, called the celestial sphere, the sun as well as all other objects in the solar system move through a plane within this celestial sphere,” Daylan said. called the ecliptic plane.
“While doing so, the sun will change its declination,” he said. Attenuation And ascension right are the two main axes of the celestial sphere. “In this frame of reference, the sun is at its southernmost position when it is the winter solstice from our perspective in the northern hemisphere.”
The winter solstice in the northern hemisphere occurs when northern pole tilted furthest away from the sun. The Arctic Circle is shrouded in darkness and experiences the longest night of the year. In the southern hemisphere, the summer solstice occurs at the same time as the south pole tilts toward the sun and the Antarctic Circle passes midnight sun.
NASA's online Ultimate Guide to Spaceflight includes a section on The celestial sphere has illustrations for those who want to explore this idea further.
The low position of the sun during the winter solstice will make you noon shadow must be exceptionally long. While it is important to humans, the solstice doesn't have much significance to the larger universe.
“The solstices are determined by the Earth-solar system, not necessarily the entire solar system. We attach a lot of meaning to it because the sun is sacred to us and its position on the celestial sphere, chronologically throughout the year, is very important,” Daylan said. “It sets the climate. Throughout the year, it tells us when the crop will reach maturity. So that's very important, especially for historical civilizations.”
Time to celebrate
From yuzu bath coming in Japan Sunday celebration In Peru, cultures around the world have a long history of celebrating the winter solstice. Contemporary Druids and archaeologists in the UK continue to care for the Stonehenge monument during this time of year. The interests of the two groups sometimes coincide, but they often disagree on issues such as display Human remains found at Stonehenge.
Below, during the winter solstice, you can watch a livestream of the sunrise broadcast on YouTube from Stonehenge.