During aphelion, our planet receives 7 percent less sunlight than in January, but changes in the planet's orbit are not what causes our seasons.
在遠日點，我們的星球比1月份少了7％的陽光，但是地球軌道的變化並不是導致我們季節更迭的原因。
Sweltering temperatures on the surface of Earth's northern hemisphere notwithstanding, the sun and Earth are currently three million miles farther from each other than when they're closest.
Credit: NASA Goddard
儘管地球北半球地表溫度很高，但太陽和地球之間的距離比距離最近的時候要遠300萬英裡。
Credit：NASA Goddard
On Friday, Earth will swing toward the outermost point in its orbit, known as aphelion. You, me and everyone on the planet will be three million miles farther from the sun than when we are closest to it.
星期五，地球將向被稱為遠日點的其軌道的最外點運動。你，我和這個星球上的每個人離太陽的距離都比距離最近的時候要遠300萬英裡。The change occurs because our planet's orbit is not perfectly circular. Instead, it is squashed into an ellipse with the sun offset from the center - an effect that causes Earth to orbit to its farthest point every July and its innermost point, or perihelion, every January (the exact dates vary slightly from year to year).
之所以會發生這種變化，是因為我們星球的軌道並不是完美的圓形。相反，它被壓成一個橢圓形，太陽從中心偏移 - 這一效應導致地球每年7月繞軌道運行到它的最遠點，每年1月運行到它的最內點或近日點（確切日期每年略有不同）。So, while record-breaking temperatures and raging wildfires in the Northern Hemisphere might lead you to believe the sun is punishingly close right now, remember that it is just the opposite. In fact, the extra distance causes the amount of received sunlight to drop by 7 percent compared to January.
因此，儘管北半球創紀錄的高溫和猛烈的山火可能會讓你相信現在的太陽離我們近在咫尺，但請記住，事實恰恰相反。事實上，與1月相比，增加的距離導致接收到的太陽光下降了7％。But don't expect any relief from summer. Seasons on Earth are the product of changes in the amount of direct sunlight as the planet tilts toward and away from the sun - not its orbital path. It would take a much greater swing, so that the amount of received sunlight dropped significantly, in order to notice the difference.
但是不要指望夏季能有任何緩解。地球上的季節是當地球朝太陽傾斜和遠離太陽傾斜時陽光直射量變化的產物-而不是它的軌道。它的擺動幅度要大得多，所以接收到的陽光的數量顯著下降，從而引起了巨大的變化。To consider what life would be like on a planet under these orbital circumstances, you only have to look as far as Mars, whose elliptical orbit causes the amount of received sunlight to vary by as much as 31 percent over the course of the planet's year.
要考慮在這種軌道環境下，行星上的生命是什麼樣子，你只需要看看火星，它的橢圓軌道導致接收到的太陽光量在一年中最多變化31％。"I find it amusing that the common misconception about Earth's seasons is actually true if you are on Mars," said David Grinspoon, an astrobiologist at the Planetary Science Institute. "School children on Mars will need to be taught differently."
"我覺得有趣的是，如果你在火星上，對地球季節的普遍誤解實際上是正確的，"行星科學研究所的天體生物學家David Grinspoon說。 "在火星上學的孩子需要接受不同的教育。"
Aymara indigenous people celebrating the sunrise of the southern hemisphere's winter solstice this year, also the Aymara New Year, near La Paz, Bolivia. Credit:Aizar Raldes/Agence France-Presse - Getty Images
今年，玻利維亞拉巴斯附近的艾馬拉土著居民慶祝南半球冬至的日出，也是艾馬拉新年。Credit：Aizar Raldes / Agence France-Presse - Getty Images
Just like Earth, Mars swings toward the frigid outer solar system at the peak of its Northern Hemisphere's summer and its Southern Hemisphere's winter. But because that swing is so much more dramatic, the plunge in sunlight creates a milder northern summer and a downright frigid southern winter. Later, Mars snuggles up close to the sun, leading to a milder northern winter and a simmering southern summer.
就像地球一樣，火星在北半球夏季和南半球冬季時向寒冷的外太陽系移動。但由於這種變化的幅度要大得多，在陽光的照射下會產生一個溫和的北半球夏季和一個完全寒冷的南半球冬季。隨後，火星靠近太陽，導致了溫暖的北半球冬季和悶熱的南半球夏季。"It's like toasting your marshmallow slowly from a safe distance above the campfire, then swooping in close for the nice quick char," said Tanya Harrison, a planetary scientist at Arizona State University, referring to that southern summer.
亞利桑那州立大學的行星科學家Tanya Harrison在談到火星南半球的夏天時說："這就像是在篝火上方的安全距離慢慢地烤著你的棉花糖，然後在近距離俯衝，把糖燒焦。"***
公益科普隨手轉發
歡迎轉載，聯繫我們：ljesy520@vip.qq.com