Delicate may not be the primary phrase that springs to thoughts while you consider the Milky Approach. However when Mariangela Lisanti began tinkering with the recipe for our galaxy, she discovered it surprisingly fragile.

Lisanti, a particle physicist at Princeton College, was simulating what would occur if darkish matter – the mysterious stuff thought to account for over 80 per cent of all of the matter within the universe – was extra unique than researchers usually assume. She swapped a small fraction of normal darkish matter with one thing extra complicated. “We thought, we’re solely including 5 per cent, every thing might be tremendous,” she says. “After which we simply broke the galaxy.”

There may be good purpose for such meddling. Because the Eighties, astronomical indicators have pointed in direction of darkish matter being a single kind of slow-moving particle that doesn’t work together with itself. Particle physicists have gone to nice lengths to seek for that particle. However many years later, it stays a no-show – maybe as a result of darkish matter isn’t how we now have tended to think about it.

Lately, a collection of galactic anomalies has sparked a scramble to discover options. This “complicated” darkish matter could be so simple as sub-atomic particles that bounce off one another, or as sophisticated as households of darkish particles that kind darkish atoms, stars and even galaxies. There’s a daunting number of prospects.

However now, observations of anomalies in our galaxy lastly promise to assist us slim down the choices. And with…