Stormy sky. This strangely shaped storm passed over Europe in mid-March. It brought a plume of dust from the Sahara Desert that turned the skies orange across the Iberian Peninsula, before it travelled north to Scandinavia, the United Kingdom and Russia. According to the European Union’s Earth-observation programme Copernicus — whose satellite captured this image — the unusual weather system also caused higher-than-average temperatures and rainfall over the Arctic Circle and along the Norwegian fjords, whereas snow was recorded in Turkey.
Nano skyscrapers. Using a 3D printer, researchers have built minuscule tower blocks for bacteria, creating a system that can generate electricity from sunlight and water. The tiny pillars — coloured green in this electron-microscopy image — are just 600 micrometres high and have a branching, densely packed structure that provides surfaces for the bacteria to grow on. They are made of metal oxide nanoparticles, so that they can act as electrodes harvesting waste electrons that the bacteria generate during photosynthesis. “The electrodes have excellent light-handling properties, like a high-rise apartment with lots of windows,” says lead author Jenny Zhang, a bioinorganic chemist at the University of Cambridge, UK. They “allow for a balance between lots of surface area and lots of light — like a glass skyscraper”. The technique proved more efficient than other methods of producing bioenergy from photosynthesis.