Icy ink. This tardigrade is sporting what is perhaps the world’s tiniest ‘tattoo’, shown as highlighted dots in this microscope image. Researchers used a technique called ice lithography, harnessing an electron beam to etch the pattern into a layer of ice coating the tardigrade. The beam transforms the frozen substance into a compound that sticks to the tardigrade’s skin, leaving the design visible when the rest of the ice evaporates. The extremely high precision of this method means it could have applications in biomedical engineering, the scientists who developed it say. They are now working on tattooing even smaller organisms, including bacteria, in the same way.
冰墨刺青。这只缓步动物（水熊虫）身上或许拥有世界上最小的“纹身”，图中高亮点即为显微镜下显示的图案。研究人员采用了一种名为冰刻的技术，利用电子束在覆盖水熊虫的冰层上蚀刻出图案。电子束将冰冻物质转化为一种能附着于水熊虫表皮的化合物，当其余冰层蒸发后，图案依然清晰可见。开发该技术的科学家表示，这种方法具有极高的精确度，有望应用于生物医学工程领域。目前他们正尝试用同样方式为更微小的生物（包括细菌）进行纹身。

Adapted from Nano Lett. 15, 6168–6175 (2025).
改编自《纳米快报》15, 6168–6175 (2025)。

A bright green ring-necked parakeet poses for a portrait amongst pale pink cherry blossoms

Spring scene. A ring-necked parakeet (Psittacula krameri) sits surrounded by pale pink cherry blossom in St James’s Park, London. These colourful birds are native to Africa and southern Asia, but have been a common sight in the city for decades as escaped pets have established populations. The species has thrived and its range expanded considerably over the past ten years, perhaps as a result of warmer winters.
春日景象。一只环颈鹦鹉（Psittacula krameri）栖息在伦敦圣詹姆斯公园淡粉色的樱花丛中。这些色彩斑斓的鸟类原产于非洲和南亚，但几十年来，由于逃逸的宠物鸟在此繁衍生息，它们已成为伦敦常见的风景线。过去十年间，该物种数量激增，分布范围显著扩大，或许与冬季气候变暖有关。

Vuk Valcic/Zuma/eyevine

Dying star. NASA’s James Webb Space Telescope has taken the most detailed image so far of planetary nebula NGC 1514, which is made up of two central stars surrounded by a huge, slightly hourglass-shaped cloud of gas and dust. The scene has been at least 4,000 years in the making, as one of the central stars has cooled and ejected material from its outer layers.
垂死之星。美国宇航局詹姆斯·韦伯太空望远镜拍摄了迄今为止最详细的行星状星云 NGC 1514 图像，该星云由两颗中央恒星组成，周围环绕着一个巨大的、略呈沙漏状的气体和尘埃云。这一景象的形成至少已有 4000 年，其中一颗中央恒星冷却并喷发出其外层物质。

NASA, ESA, CSA, STScI, Michael Ressler (NASA-JPL), Dave Jones (IAC)

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Baby giant. Scientists have filmed a colossal squid (Mesonychoteuthis hamiltoni) in its natural habitat for the first time. The creature is a juvenile measuring just 30 centimetres long, and will eventually become opaque as it grows into its 7-metre-long adult body. A remote-controlled vehicle spotted it at a depth of 600 metres near the South Sandwich Islands in the South Atlantic Ocean.
巨型幼崽。科学家首次拍摄到了大王酸浆鱿（学名：Mesonychoteuthis hamiltoni）在其自然栖息地的画面。这只幼年个体仅 30 厘米长，随着生长至 7 米长的成体，其身体将逐渐变得不透明。遥控潜水器在南大西洋南桑威奇群岛附近 600 米深处发现了它。

Schmidt Ocean Institute 施密特海洋研究所

A group of Buddhist monks varying in ages stand on a mound of rubble as they clear up debris from a damaged building

Rare rupture. Monks clear up rubble at the Thahtay Kyaung Monastery in Mandalay, Myanmar, one of thousands of structures damaged after a magnitude-7.7 earthquake hit the country on 28 March. The quake seems to have been of a rare type known as supershear, scientists say, in which the energy of a rupture moves exceptionally fast through the ground, amplifying its destructive power. It is estimated to have killed more than 3,000 people and injured many more.
罕见断裂。3 月 28 日缅甸发生 7.7 级地震后，曼德勒 Thahtay Kyaung Monastery 的僧侣们正在清理废墟，这是数千座受损建筑之一。科学家表示，此次地震似乎属于罕见的超剪切型，断裂能量以异常速度在地表传播，放大了破坏力。据估计地震已造成 3000 多人死亡，更多人受伤。

Sai Aung Main/AFP/Getty

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Dazzling glow. NASA astronaut Don Pettit captured this incredible footage of a swirling green aurora from the ISS as it travelled over Earth’s Southern Hemisphere. The lights appear as a result of charged particles from the Sun interacting with Earth’s magnetic field, which ionizes molecules in Earth’s upper atmosphere and causes them to glow. Green colours tend to be produced by oxygen-containing molecules such as O₂ and ozone.
炫目极光。NASA 宇航员唐·佩蒂特从国际空间站拍摄到这段令人惊叹的绿色极光旋涡影像，当时空间站正飞越地球南半球上空。这些光芒是太阳带电粒子与地球磁场相互作用的结果，该过程电离了地球高层大气中的分子并使其发光。绿色通常由含氧分子如 O ₂ 和臭氧产生。

Don Pettit/NASA 唐·佩蒂特/美国宇航局

University students take part in mangrove planting to mark Earth Day in Banda Aceh.

Friends of the Earth. University students marked Earth Day on 22 April by planting mangrove seedlings in Banda Aceh, Indonesia. The country is home to an estimated 20% of the world’s mangroves and has the highest richness of species, but many of its mangrove forests have been lost to land development and farming, and others required extensive restoration after the Indian Ocean tsunami in 2004. Community-led planting projects aim to ensure the survival of this vital but delicate ecosystem.
地球之友。为纪念 4 月 22 日地球日，印尼班达亚齐的大学生种植了红树幼苗。该国拥有全球约 20%的红树林，物种丰富度最高，但由于土地开发和农业活动，许多红树林已消失，另一些在 2004 年印度洋海啸后需要大规模修复。社区主导的种植项目旨在保护这一重要而脆弱生态系统的存续。

Riska Munawarah/Reuters Riska Munawarah/路透社

A square image made up of sixteen smaller individual square images, resembling a grid composite, each made up of circular patterns in varying shapes and in various shades of red

Perfect curves. This image, which offers a way to visualize mathematical functions called isogenies, was created using a tool called Sagemath by Ryan Rueger, a cryptography researcher at IBM Research in Zurich, Switzerland. They describe an object called a supersingular elliptic curve. Various characteristics, for example the number of swirls, convey information about the curve’s complexity. The Escher-like illustrations won a distinction at the Swiss National Science Foundation’s 2025 scientific image competition.
完美曲线。这张图像由瑞士苏黎世 IBM 研究院的密码学研究者 Ryan Rueger 使用 Sagemath 工具创建，旨在可视化一种称为同源性的数学函数。它描绘了一种名为超奇异椭圆曲线的对象，其各种特征（如漩涡数量）传递着曲线复杂度的信息。这幅埃舍尔风格的插图在瑞士国家科学基金会 2025 年科学图像竞赛中获得了优异奖。

Ryan Rueger 瑞安·鲁格

Rocket rollout. On 8 April, NASA astronaut Jonny Kim travelled to the International Space Station (ISS) on board a Soyuz rocket, together with Roscosmos cosmonauts Sergey Ryzhikov and Alexey Zubritsky, to begin an 8-month stint in space contributing to research on biology, Earth sciences and technology. This photograph shows the rocket raised into the vertical position on the launch pad at the Baikonur Cosmodrome in Kazakhstan. The trio safely docked at the ISS after a three-hour journey.
火箭启程。4 月 8 日，NASA 宇航员 Jonny Kim 与俄罗斯航天局宇航员 Sergey Ryzhikov、Alexey Zubritsky 共同搭乘联盟号火箭前往国际空间站(ISS)，开启为期 8 个月的太空驻留，参与生物学、地球科学与技术研究。照片记录了火箭在哈萨克斯坦拜科努尔发射场竖立于发射台的情景。三人组在经历三小时飞行后安全对接空间站。

Joel Kowsky/NASA/Getty 乔尔·考斯基/美国宇航局/盖蒂图片社

Eye in the Antarctic. China has unveiled a 3.2-metre aperture radio telescope at its Zhongshan scientific research station in Antarctica. Over the past two years, researchers working on the facility — called the Three Gorges Antarctic Eye — had to overcome key technical hurdles, such as adapting equipment to withstand Antarctica’s harsh sub-zero temperatures and hurricane-force winds. The telescope will help astronomers to unravel the dynamics of interstellar gas and the processes of star formation, according to China Three Gorges University in Yichang, which co-led the development with Shanghai Normal University.
南极之眼。中国在其南极中山科考站揭幕了一台口径 3.2 米的射电望远镜。过去两年间，参与建设该设施（名为"南极天眼"）的研究人员攻克了多项关键技术难题，例如使设备适应南极极寒及飓风级强风环境。据联合主导项目开发的宜昌三峡大学与上海师范大学透露，该望远镜将助力天文学家解析星际气体动力学及恒星形成过程。

Xinhua/Shutterstock 新华社/Shutterstock