Nature Podcast

00:47 The mystery of the missing dark matterDark matter makes up most of the matter in the Universe, and is thought to be needed for galaxies to form. But four years ago, astronomers made a perplexing, and controversial discovery: two galaxies seemingly devoid of dark matter. This week the team suggests that a cosmic collision may explain how these, and a string of other dark-matter-free galaxies, could have formed.Research article: van Dokkum et al.News and Views: Giant collision created galaxies devoid of dark matter08:39 Research HighlightsHow fossil fuel burning has caused levels of helium to rise, and a high-efficiency, hybrid solar-energy system.Research Highlight: Helium levels in the atmosphere are ballooningResearch Highlight: Flower power: ‘Sunflower’ system churns out useful energy10:49 Researchers experiences of the war in UkraineWe hear the stories of scientists whose lives have been affected by Russia’s invasion of Ukraine, including researchers who have become refugees, soldiers and activists i