至点 Solstice
(重定向自Solstitial point)




二至点(亦称至点)可以是太阳在一年之中离地球赤道最远的两个事件中的任何一个,英文的字源(solstice) 来自拉丁文的太阳(sol)和保持直立(sistere),因为在至点时太阳直射的地球纬度是他能抵达的最南或最北的极值,而至点所在之日是一年之中日夜长短差异最大的一天。至点和分点通常与季节有关,在一些区域他们被做为季节的起点或分界点,有些区域则将之作为中间点。例如在北半球的英国,在六月至点前后的一段时期被称为仲夏,而仲夏日被订为夏至之后2或3日的6月24日。
![A solargraph taken from the Atacama Pathfinder Experiment at the Llano de Chajnantor Observatory in the southern hemisphere. This is a long-exposure photograph, with the image exposed for six months in a direction facing east of north, from mid-December 2009 until the southern winter solstice in June 2010.[4] The sun's path each day can be seen from right to left in this image across the sky; the path of the following day runs slightly lower, until the day of the winter solstice, whose path is the lowest one in the image.](/uploads/202502/12/lossy-page1-220px-Solargraph_APEX.tif5041.jpg)
