格拉斯顿伯里山丘上的日出，英格兰 View of Glastonbury Tor from Walton Hill, Somerset, England (© Guy Edwardes/Minden Pictures)

格拉斯顿伯里山丘上的日出，英格兰 View of Glastonbury Tor from Walton Hill, Somerset, England (© Guy Edwardes/Minden Pictures)

夏季来临 Summer a-rising

Summer solstice

The summer solstice, also known as an estival solstice or midsummer, occurs when one of Earth's poles has its maximum tilt toward the Sun. It happens twice yearly, once in each hemisphere (Northern and Southern). For that hemisphere, the summer solstice is when the Sun reaches its highest position in the sky (for areas outside of the tropics) and is the day with the longest period of daylight. Within the Arctic circle (for the northern hemisphere) or the Antarctic circle (for the southern hemisphere), there is continuous daylight around the summer solstice. On the summer solstice, Earth's maximum axial tilt toward the Sun is 23.44°. Likewise, the Sun's declination from the celestial equator is 23.44°.

Since prehistory, the summer solstice has been seen as a significant time of year in many cultures and has been marked by festivals and rituals. Traditionally, in many temperate regions (especially in Europe), the summer solstice is seen as the middle of summer and referred to as "midsummer". Today, however, in some countries and calendars it is seen as the beginning of summer.

夏至

夏至，也被称为夏至或仲夏，发生在地球的两极之一最大程度地向太阳倾斜的时候。每年发生两次，每个半球（北半球和南半球）一次。对于那个半球来说，夏至是太阳在天空中达到最高位置（对于热带以外的地区）的时候，也是日照时间最长的一天。在北极圈（北半球）或南极圈（南半球）内，夏至前后有连续的白天。夏至，地球对太阳的最大轴向倾斜为23.44°。同样，太阳从天球赤道的赤纬为23.44°。

自史前以来，在许多文化中，夏至一直被视为一年中重要的时间，并以节日和仪式为标志。传统上，在许多温带地区（尤其是欧洲），夏至被视为仲夏，被称为“仲夏”。然而，今天，在一些国家和日历中，这被视为夏季的开始。