For the first time, ESA's Planck space telescope has detected a bridge of hot gas connecting a pair of galaxy clusters 10 million light-years apart.
Astronomers have produced the most comprehensive map yet of the universe's dark matter, finding it spread in a spiderweb around which ordinary matter coalesces.
NASA scientists are using data collected by the Hubble Space Telescope to map the distribution of dark matter in 25 massive clusters of galaxies.
Einstein famously said that no amount of experimentation would prove him right. But two new studies have backed up his General Theory of Relativity, and one significantly undermines a rival theory.