Expansion microscopy. This small colony of green algae (Stephanosphaera pluvialis) was captured using an imaging technique called expansion microscopy. These freshwater algae normally live in rainwater puddles and rock pools. Here, their microtubules have been labelled in green, and areas of high protein density labelled in magenta. The method involves physically enlarging biological samples by embedding them in a polymer gel that swells.

Felix Mikus, Dudin & Dey Labs

Sleeping parasites. Trypanosomid flagellates (Blechomonas lauriereadi) are parasites that live in the extracellular spaces — typically in their hosts’ blood plasma and body fluids. The parasites can cause sleeping sickness if they infect humans, and animal trypanosomiasis in cattle and horses. Here, the organisms’ microtubules are labelled in pink and their extensive mitochondria in green, using expansion microscopy. The images are part of ongoing efforts to build an atlas of microbial eukaryotes.

Felix Mikus, Dudin & Dey Labs

Lucero’s journey. Lucero, an eastern Pacific leatherback turtle (Dermochelys coriacea) in Ecuador, is the first of her species to receive a satellite tag, for scientists to track her location. “The data collected will provide fishers and scientists with valuable information on leatherback movement patterns and critical habitat-use areas, helping to better target conservation efforts,” said Callie Veelenturf, a marine biologist at The Leatherback Project in Norfolk, Massachusetts. Lucero is the Spanish word for morning star and refers to the planet Venus, which has helped people to navigate the Pacific for hundreds of years.

Will Lucero

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Veins of Earth. A satellite image shows some of the world’s rivers aglow as blue threads spread across Earth — a view never seen before in such detail or at such a scale. The image was captured by a space mission led by NASA and the French space agency CNES, which tracked nearly 127,000 rivers around the world between October 2023 and September 2024. Analysing nearly 1.7 million satellite observations, researchers mapped riverbeds as well as changes in water storage. Their findings, published this month, estimated that rivers gain and lose almost 314 trillion litres of water — about 28% less of a swing than the lowest previous estimates.

Greg Shirah (NASA/GSFC)

Tree beams. The tips of trees glow during thunderstorms, but their light is too faint for the human eye to see. For the first time, researchers have observed these weak electrical discharges, known as coronae, in the wild. During a storm in Pembroke, North Carolina, researchers captured coronae on sweetgum (Liquidambar styraciflua) and loblolly (Pinus taeda) pine trees. The glow hopped from leaf tip to leaf tip and lasted for up to 3 seconds. These images show the tips of spruce needles (Picea) glowing blue in a laboratory experiment in which researchers artificially induced coronae.

William Brune

Life follows death. Photographer Nelson Milano came across chocolate slime mould (Stemonitis splendens) on a decaying log in Freeport Community Park, Pennsylvania. Milano, an entomologist, found a mass of what he thought looked like chocolate cake and mentioned it to a colleague, who immediately said, “chocolate slime mould!” “I’ve always been fascinated by minute organisms, and this looked like a sci-fi creature to me,” Milano added. The shot was shortlisted for the Close-up Photographer of the Year (CUPOTY) challenge under the theme of death and decay (see below for a selection of other shortlisted images).

Nelson Milano/CUPOTY

Jacek Hensoldt/CUPOTY

Ed Phillips/CUPOTY

Hans Enderl/CUPOTY

Sophie Mijnhout/CUPOTY

Joseph Ferraro/CUPOTY

Indranil Basu Mallick/CUPOTY

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Jacek Hensoldt/CUPOTY

Ed Phillips/CUPOTY

Hans Enderl/CUPOTY

Sophie Mijnhout/CUPOTY

Joseph Ferraro/CUPOTY

Indranil Basu Mallick/CUPOTY

Waste to worth. 8 March marked International Women’s Day — a time to recognize and honour women around the world. In this photograph, geoscientist Rita Idehai stands beside stacked plastic bales near a recycling facility in Abuja, Nigeria. In 2018, Idehai launched her company, Ecobarter, which collects and repurposes plastic waste. The company helps women across Nigeria to turn plastic waste into bags, clothing and fashionable accessories, and says it has recovered more than 1,200 tonnes of waste and prevented 2,000 tonnes of carbon emissions. Through her work, Idehai has created a system that monetizes plastic waste for donors and fights plastic pollution and poverty.

Light Oriye Tamunotonye/AFP via Getty

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Weird begets weird. A three-le

See the intricate worlds of parasites and algae — March’s best science images