沃森峰上空的彩虹, 巨人柱国家公园, 亚利桑那州, 美国 Rainbow over Wasson Peak, Saguaro National Park, Arizona, USA (© Frank Staub/Getty Images)

天空无极限 The sky is the limit

沃森峰上空的彩虹, 巨人柱国家公园

您是否曾偶然发现彩虹，并感受到一股幸福感？你是否曾想在雨后捕捉阳光下的七彩奇观？从北欧神话中的众神，到爱尔兰妖精的聚宝盆，彩虹一直被赋予神秘的意义。但除了传说，彩虹背后的科学同样引人入胜，德国物理学家狄奥多里克在1304年给出了第一个合理的解释。他发现，阳光进入雨滴后会发生折射，然后在雨滴内反射，再折射出雨滴。这个过程将光线分解成不同的颜色，形成我们看到的光谱。虽然我们知道 “ROYGBIV”（红、橙、黄、绿、蓝、靛、紫）是彩虹的基本颜色，但彩虹实际上包含了数百万种颜色的渐变混合物。

并非所有彩虹看起来都相同。当第二道较暗且颜色顺序相反的彩虹出现在主彩虹上方时，便形成了双彩虹。今日图片展示了美国亚利桑那州萨瓜罗国家公园瓦森峰上空的一道绚丽彩虹。在干旱少雨的沙漠景观中，仙人掌与岩石山坡构成的背景下，这道彩虹格外醒目，证明了即使在最干燥的土地上，大自然依然能带来惊喜。

National Find a Rainbow Day

Have you ever spotted a rainbow and felt a little lucky? National Find a Rainbow Day, celebrated today, is all about looking to the sky for that magical mix of sun and rain. Nature's color wheel has long been linked to myths and legends, from Norse gods to the Irish leprechaun's pot of gold. But beyond folklore, the science behind rainbows is just as compelling. The first real explanation came from Theodoric of Freiberg, a German physicist, in 1304. He discovered that rainbows form when sunlight enters a raindrop, bends, reflects inside, and then bends again as it exits. This process splits light into its colors, creating the spectrum we see. The classic 'ROYGBIV' (red, orange, yellow, green, blue, indigo, and violet) doesn't tell the whole story—rainbows contain millions of colors blended together.

Not all rainbows look the same. Double rainbows occur when a fainter, reversed arc appears above the main one. Moonbows happen at night when moonlight refracts through water droplets. The rare supernumerary rainbow features extra pastel bands inside the primary arc. Today's image features a rainbow over Wasson Peak in Saguaro National Park, Arizona. Against a backdrop of desert cacti and rocky slopes, the vibrant arc stands out in a place where rain is scarce, proving that even the driest landscapes can surprise you.

凯恩维尔附近荒地的砂岩地层, 犹他州, 美国 Sandstone formations in the badlands near Caineville, Utah (© Chris Moore/TANDEM Stills + Motion)

时间的波浪 Waves of time

凯恩维尔附近荒地的砂岩地层, 犹他州, 美国

蜿蜒起伏的砂岩脊绵延于犹他州凯恩维尔荒地，宛如大自然在石头上绘制的笔触。这些地貌由细粒沉积物构成，最初沉积在古代河流三角洲和内陆海洋中，随后逐渐硬化为岩石。随着时间的推移，侵蚀作用穿透了这些地层，露出流动般的波纹状图案。沉积岩层记录着气候变迁和古老地貌的演变。今日图片中，这片荒凉的土地看似毫无生机，但在早春时节，降雨会让大地铺满紫色和黄色的小花。一天的不同时刻，光影不断变化，展现出不同的角度与风貌，为摄影师和游客提供了丰富的观赏体验。尽管这片崎岖不平的地形大部分仍然保持原始状态，但部分区域地势较为平缓，允许游客在无需剧烈攀爬的情况下轻松探索。

荒地广布于除南极洲以外的所有大陆。早期探险者在穿越这些艰难地形时遭遇重重困难，因此赋予它们“荒地”之名。古生物学家经常能在这里发现史前生物的化石遗骸。尽管环境极端，这些土地依然孕育着丰富的生命，包括沙漠植物、蜥蜴和鸟类。

Sandstone formations in the badlands near Caineville, Utah

Wavy sandstone ridges stretch across the Caineville Badlands in Utah, resembling nature's brushstrokes on stone. These formations are made of fine-grained sediment that settled in ancient river deltas and inland seas and later hardened into stone. Over time, erosion carved through the layers, exposing flowing, ripple-like patterns. The sedimentary layers tell a story of shifting climates and ancient landscapes. The barren land may appear lifeless, but during early spring, rainfall causes the terrain to be blanketed with tiny purple and yellow flowers. While much of the terrain remains rugged, some areas offer easy access, allowing visitors to explore without strenuous hiking.

Badlands exist on every continent except Antarctica. Early explorers named them after struggling to navigate harsh terrains. Fossil hunters frequently uncover remnants of prehistoric creatures in the eroded hills. Despite the extreme conditions, badlands support a wide range of life, including desert plants, lizards, and birds.

黄昏下的奥斯图尼, 普利亚, 意大利 Ostuni at dusk, Apulia, Italy (© Feng Wei Photography/Getty Images)

普利亚的“白色之城” The White City of Apulia

奥斯图尼，普利亚，意大利

这座历史悠久的城市坐落在亚得里亚海的山顶，以其迷宫般的白色建筑、蜿蜒的小巷和阳光普照的广场吸引着游客。欢迎来到意大利普利亚大区的奥斯图尼！普利亚位于意大利“靴子”形版图的“脚后跟”，拥有该国大陆地区最长的海岸线，这里不仅有迷人的海滩、壮丽的悬崖，还有如今日图片中的奥斯图尼这样美丽的城市。

奥斯图尼被称为“白色之城”，但这些建筑的白色外墙不仅仅是美观，更有实际用途：白色涂层可以反射阳光，从而保持室内凉爽。市中心坐落着哥特式风格的奥斯图尼大教堂，其精美的玫瑰窗可追溯至15世纪。附近 2017 年开放的教区博物馆收藏了来自当地教堂和修道院的珍贵文物，其中包括拜占庭圣像、普利亚雕塑和 18 世纪的蜡制十字架。自由广场是奥斯图尼这座城市的活力中心，这里矗立着圣奥隆佐石柱，以纪念这位在 1657 年拯救奥斯图尼免受瘟疫侵袭的守护神。无论你是热爱历史，还是喜欢漫步于如画的街道，奥斯图尼都能为你带来独特的体验。

Ostuni, Apulia, Italy

Perched on a hilltop overlooking the Adriatic Sea, there is a historic city that enchants visitors with its labyrinth of whitewashed buildings, winding alleyways, and a sun-drenched piazza. Welcome to Ostuni, in the Apulia region of Italy. Located in the heel of Italy's 'boot,' Apulia has the longest coastline of any mainland region in the country and is home to numerous attractions, including beaches, cliffs, and charming cities like the one we see in today's image.

Known as the White City, Ostuni's white facades serve a practical purpose—reflecting the sun's rays to keep interiors cool. The center of the city features the Gothic-style Ostuni Cathedral, which boasts an intricate rose window dating back to the 15th century. Nearby, the Diocesan Museum, opened in 2017, houses treasures from local churches and monasteries, including Byzantine icons, Apulian sculptures, and an 18th-century wax crucifix. Piazza della Libertà, Ostuni's lively hub, is home to the Column of St. Oronzo, which honors the patron saint who saved the city from the plague in 1657. Whether you're drawn by history or simply love wandering through idyllic streets, Ostuni has something for everyone.

悉尼港鸟瞰图，新南威尔士州，澳大利亚 Aerial view of Sydney Harbour, New South Wales, Australia (© jamenpercy/Getty Images)

尽享美景 Harboring nice views

克逊港，新南威尔士州，澳大利亚

今日图片展示了悉尼的著名景点，波光粼粼的海面映衬着世界级地标：杰克逊港，也就是人们更熟知的悉尼港。在图片右侧，可以俯瞰到悉尼歌剧院，这座建筑杰作以白色帆状外壳闻名，在澳大利亚的阳光下熠熠生辉作为联合国教科文组织世界遗产，该建筑由丹麦建筑师约恩·乌松 设计，耗时 14 年建成。如今，它每年举办超过 1500 场演出，是全球最知名的文化艺术中心之一。图片左侧，横跨港湾的是悉尼海港大桥，因其拱形钢架结构而被亲切地称为“衣架”，连接着悉尼的南北两岸。这座桥1932 年开通时，是世界上最宽的长跨度桥梁。喜欢冒险的游客还可以攀登桥顶，到达 440 英尺的高度，俯瞰令人惊叹的悉尼全景。

每年新年前夜，悉尼港都会变身为世界级烟花秀的舞台，吸引超过百万名现场观众，以及全球数百万电视观众共同观看这场盛大的视觉盛宴。烟花从大桥和港口上的驳船一同点燃，成为无数人的人生必体验清单之一。无论何时来到悉尼港，这里都能为游客带来融合历史、冒险与自然之美的非凡体验。

Sydney Harbour, New South Wales, Australia

Today's photo features a spot in Sydney, Australia, where shimmery waters meet famous landmarks: Port Jackson, more commonly known as Sydney Harbour. In the center, we have a bird's-eye view of the Sydney Opera House, an architectural icon with sail-like shells that shine bright under the Australian sun. Designed by Danish architect Jørn Utzon, this UNESCO World Heritage Site took 14 years to complete and hosts over 1,500 performances annually. Just across the harbor, on the left side of the picture, the Sydney Harbour Bridge—affectionately called 'the Coathanger' for its arching steel frame—connects the city's northern and southern shores. When it opened in 1932, it was the world's widest long-span bridge. Adventurous visitors can climb its 440-foot summit for breathtaking panoramic views.

Every New Year's Eve, this waterfront transforms into the stage for spectacular fireworks displays, attracting over a million spectators and millions more watching worldwide. The dazzling show, launched from the bridge and barges across the harbor, is a bucket-list experience. No matter what time of year, Sydney Harbour promises an experience filled with history, adventure, and beauty at every turn.

卡里佐平原国家纪念碑的超级花期，加利福尼亚州，美国 Superbloom in Carrizo Plain National Monument, California (© Robb Hirsch/TANDEM Stills + Motion)

花海绽放 Burst of blooms

卡里佐平原国家纪念碑的超级花期，加利福尼亚州

在沙漠地区，大片花朵绽放的景象并不常见，但在超级花海期间，原本干旱的土地将被无尽的花田覆盖。这种罕见的自然现象发生在美国加利福尼亚州和亚利桑那州，当雨季来临，沉睡在土壤中的野花种子被唤醒，形成壮观的花海景观。加利福尼亚州的超级花海通常每十年出现一次，然而21 世纪持续的干旱使其愈发罕见。超级花海不仅展示了加州丰富的植物多样性，还吸引游客前来观赏，短暂地促进当地经济发展。今日图片中的卡里佐平原国家纪念碑正是观赏这一壮观景象的最佳地点之一。这片广阔的封闭型草原位于加利福尼亚州圣路易斯奥比斯波县东南部，全长约50英里，宽约15英里。坦布洛山脉和卡连特山脉的山丘，以及苏打湖附近的谷地，都会变成一片五彩斑斓的野花拼图，绚丽至极。你曾有幸见过超级花海吗？

Superbloom in Carrizo Plain National Monument, California

It's not every day you see a desert burst into colors, but during a superbloom, arid land is covered with endless stretches of flowers. This rare phenomenon happens in California and Arizona when the rainy season awakens wildflower seeds that have been lying dormant in the soil. Superblooms in California typically occur once a decade, but prolonged droughts in the 21st century have made them increasingly less frequent. Drawing attention to California's diverse flora and rural federal lands, these events offer temporary boosts to local economies.

One of the best spots to witness this spectacular phenomenon is Carrizo Plain National Monument, seen in today's image of a superbloom in 2017. A vast enclosed grassland in southeastern San Luis Obispo County, California, this spot is approximately 50 miles long and 15 miles wide. Here, the hills of the Temblor and Caliente Ranges, along with the valley floor near Soda Lake, transform into a patchwork of colorful wildflowers when conditions are right. Have you ever had the chance to see a superbloom?

希罗德·阿提库斯剧场，雅典卫城，希腊 Odeon of Herodes Atticus theater, Acropolis of Athens, Greece (© f11photo/Getty Images)

向戏剧致敬 A standing ovation for theaters

世界戏剧日

灯光亮起，帷幕升起，今天是世界戏剧日。自 1961 年以来，国际戏剧协会每年都会举办这一年度盛事，旨在让全球观众和艺术家共同庆祝戏剧的魅力，感受叙事的力量、创造力和文化的交汇。每年，国际戏剧协会都会邀请一位享誉全球的戏剧界代表发表主题演讲，这些演讲被翻译成50多种语言，与世界各地的人们分享。这些演讲强调了戏剧在社会中的重要作用，它既可以是作为现实的镜子，也是推动变革的力量，或是激发想象力的庇护所。无论是莎士比亚的独白，还是先锋实验剧场，戏剧艺术始终在发展演变，但它的核心始终不变：人与人之间的情感联系。

那么，在这样一个重要的日子里，哪里才是最佳的庆祝地点呢？这座位于希腊雅典卫城脚下的赫罗德·阿提库斯剧场，近两千年来一直是戏剧与音乐的舞台。剧场建于公元 161 年，由富有的罗马人希罗德斯·阿提库斯为纪念其亡妻而建。从古典悲剧到现代音乐会，这里仍在续写戏剧艺术的辉煌篇章。尽管历经数个世纪，其卓越的声学设计依然让每一场演出都能完美回响。

World Theater Day

Lights on, curtains rise—it's World Theater Day. Since 1961, this annual event by the International Theater Institute (ITI) has united audiences and artists in a shared appreciation of storytelling, creativity, and culture. Every year, a renowned theater figure is invited by ITI to deliver a message that resonates across the industry. Their words are translated into more than 50 languages and shared with people all over the world. These messages highlight theater's role in society—be it as a mirror to reality, an agent of change, or a refuge for the imagination. From Shakespeare's soliloquies to experimental avant-garde productions, theater has continuously evolved while holding onto its core: human connection.

So, what better place to celebrate today than at the Odeon of Herodes Atticus? Located at the foot of the Acropolis in Athens, Greece, this stone Roman theater has been setting the scene for performances for nearly two millennia. Built in 161 CE by the wealthy Roman Herodes Atticus in memory of his wife, the ancient venue has hosted everything from classical tragedies to modern-day concerts. Despite the passing centuries, its acoustics still strike the right chord.

鲍曼附近日落时分的闪电和风暴云，内布拉斯加州，美国 Lightning and storm clouds at sunset near Bowman, Nebraska (© john finney photography/Getty Images)

雷鸣不可阻挡 You can't silence thunder

世界气象日

今天，我们庆祝世界气象日，这一纪念日旨在纪念1950年世界气象组织的成立。每年的世界气象日都会关注一个重要的全球气象议题。2025 年的主题“携手缩小预警差距”，强调及时的天气预警和早期行动对于减少灾害损失的重要性。

今日图片中展示了令人叹为观止的爬行闪电，拍摄于美国内布拉斯加州。该州以龙卷风和雷暴而闻名，尤其是在春季和夏季最为频繁。爬行闪电是一种水平移动的树状闪电，在夜空中划出壮丽的光影，彰显大自然的磅礴力量。内布拉斯加州独特的地理环境，包括广阔的大平原和频繁的雷暴，使其成为这种壮观气象现象的高发地。得益于世界气象组织在气象学领域的进步，我们如今可以更精准地预测和应对这些极端天气事件，保护生命与财产安全。

World Meteorological Day

Today, we celebrate World Meteorological Day, commemorating the founding of the World Meteorological Organization (WMO) in 1950. For the annual event, the WMO places emphasis on a different pressing topic each year. The slogan of 2025, 'Closing the early warning gap together,' highlights the importance of timely weather alerts and early action.

Pictured here is awe-inspiring anvil crawler lightning in Nebraska, a state renowned for its tornadoes and thunderstorms, typically during spring and summer. Anvil crawlers are tree-like lightning discharges that move horizontally. Nebraska's location in the Great Plains makes it a hotspot for storm activity. Thanks to the WMO's advancements in meteorology, we can better predict and respond to these dramatic weather events, safeguarding lives and property.

低地雨林上空的薄雾，丹浓谷，沙巴，婆罗洲，马来西亚 Mist over a lowland rainforest, Danum Valley, Sabah, Borneo, Malaysia (© Nick Garbutt/Alamy)

树木万岁 Long live the trees

国际森林日快乐！

3月21日是国际森林日，这一全球性纪念日旨在庆祝森林在支持生物多样性和应对气候变化方面发挥的重要作用。国际森林日由联合国于2013年首次设立，鼓励全球开展植树活动，以提高人们对森林对未来世代重要性的认识。

观察森林生物多样性的最佳地点之一，正是今日图片中的达浓谷保护区，它位于马来西亚婆罗洲岛沙巴州。这个保护区占地169平方英里，拥有1.3亿年历史的古老雨林，栖息着极为稀有的物种，包括婆罗洲猩猩、云豹和超过270种鸟类。除了丰富的生物多样性，达浓谷也是研究者的天堂，长期研究项目在此监测生态系统和野生动物，以推动保护工作。在庆祝国际森林日之际，我们应当铭记：保护森林，就是保护地球的健康。请花点时间欣赏大自然的美丽，并支持保护森林的努力，以造福子孙后代。

Happy International Day of Forests!

March 21 marks the International Day of Forests, a global observance aimed at celebrating the vital role forests play in supporting biodiversity and combating climate change. First established by the United Nations in 2013, this day encourages worldwide efforts, such as tree-planting campaigns, to raise awareness about the importance of forests and trees for future generations.

One of the most breathtaking places to observe the richness of forests is the Danum Valley Conservation Area in Sabah on the Malaysian island of Borneo, starring in today's image. This 169-square-mile sanctuary is home to an ancient rainforest, teeming with rare species like Bornean orangutans, clouded leopards, and over 270 bird species. In addition to its incredible biodiversity, the Danum Valley is also a haven for researchers, with long-term studies monitoring its ecosystem and wildlife to aid conservation efforts. As we celebrate the International Day of Forests, let's remember that protecting our trees is essential for preserving our planet's health. Take a moment to appreciate nature's beauty and support efforts to safeguard our forests for generations to come.

美丽盛开的樱花，杭州的春天，中国 Beautiful blooming cherry blossoms, Spring in Hangzhou, China (© zhangshuang/Getty Images)

春日仙境 Springtime Fairyland

杭州的春季，中国

春分有两个含义。其一是 “四季相等”。传统上，从立春到立夏之间的这段时间被称为春季，春分点位于两个节气之间，平分了春季。春分的另一个含义是 “昼夜相等”。春分时节，太阳直射赤道，昼夜等长，各为 12 小时。春分过后，除青藏高原、东北、西北和华北北部地区外，全中国进入明媚的春天。

许多花卉都在春分之后慢慢绽放，例如樱花就是春季具有代表性的花卉之一。中国古时已确有多种樱花。秦汉时期，樱花栽培就已应用于宫苑之中，距今已有2000多年的历史。唐朝时，已普遍栽种在私家庭院中。在园林美化造景中，樱花可群植形成“花海”景观，或列植为行道树，或列植种在湖畔旁。今日图片中为您带来的是杭州春季盛开的樱花和湖面的游船，这正式一处欣赏春日园林水景的绝佳之处。

红色岩层，塞多纳，亚利桑那州，美国 Red rock formations, Sedona, Arizona (© Jim Ekstrand/Alamy Stock Photo)

漩涡般的心境 A vortex state of mind

红岩，塞多纳，亚利桑那州

亚利桑那州的塞多纳是一片融合自然奇观、历史遗产与灵性体验的土地。这里坐落着壮丽的红色砂岩地貌，其火红的岩层属于施内布利山地层，由古代海洋沉积物形成，历经数百万年的地质变迁。风化与侵蚀塑造出塞多纳今日的壮观景观，使其在日出和日落时分更显绚丽夺目。这里的威尔逊山、七圣池和大教堂岩等地标，以其奇特的岩层和迷人的景致，吸引着无数游客。

然而，塞多纳不仅仅是一座地质奇观，它还承载着丰富的历史文化。美洲原住民部落曾在此定居，留下了令人惊叹的岩画、悬崖居所和印第安村落，例如蒙特祖马城堡和图齐谷国家纪念地。今天的塞多纳不仅仅是徒步旅行者的天堂，还因其能量漩涡而闻名。这些被认为具有神秘能量的地点，吸引着寻求身心疗愈的游客。这些地区的特征是扭曲生长的杜松树，以及令人屏息的壮丽景观，为塞多纳增添了一种神秘色彩。无论是徒步旅行、探索古老遗迹，还是体验灵性疗愈，塞多纳都能提供独一无二的体验。来到这里，不仅是欣赏风景，更是感受自然与心灵的奇迹！

Rock formations at Sedona, Arizona

Sedona, Arizona, is a place where nature, history, and spirituality converge amidst stunning red rock formations. These fiery sandstone creations, part of the Schnebly Hill Formation, were shaped over millions of years during the Permian Period as sediment accumulated in an ancient sea. Over time, erosion has further sculpted Sedona's landscapes, which now glow brilliantly at sunrise and sunset. Notable formations such as Wilson Mountain, Seven Sacred Pools, and Cathedral Rock offer iconic views.

Sedona isn't just a geological wonder; it's also steeped in history. Native American people have called this region home for millennia. Without any written history, most of the information about the earliest settlers comes from the archaeological ruins that remain, including rock art, cliff dwellings, and pueblos such as Montezuma Castle and Tuzigoot. Visitors can also experience Sedona's renowned energy vortexes—spiritual sites said to promote healing and balance. These areas, marked by twisted juniper trees and breathtaking views, add a mystical dimension to Sedona's allure.