Reported by Robert Lea

Artist’s impression of dark matter

© Getty

Astronomers have used a principle first proposed by Einstein over 100 years ago to map the distribution of dark matter in unprecedented detail. The team’s method managed to reveal the presence of dark matter ‘clumps’ between galaxies, showing how this mysterious substance is distributed on smaller scales. Fluctuations in the observed dark matter, identified between a distant quasar and a galaxy between that quasar and Earth, could help constrain the properties of the elusive substance.

Dark matter is troubling for scientists because, despite the fact it makes up about 85 per cent of our universe, it’s effectively invisible. This is because dark matter either doesn’t interact with any electromagnetic radiation, including visible light, or does so incredibly weakly. This means the particles that make up dark matter – whatever they are – cannot be atoms composed of electrons, protons and neutrons. These are the baryons that form the everyday matter that makes up stars, planets, our bodies and everything we see around us. It’s this puzzle that has prompted an intense search for dark matter particles. Thus far, the only way scientists can infer the presence of dark matter is by looking at the effect it has on ‘normal’ matter via gravity.