B. Altieri

In Euclid's deep fields, stars flare up that were not in any catalog. A telescope built to map dark matter has worked like a camera trap: one frame, and a cosmic explosion is already on record.

A pot of boiling water sits on the stove: the higher the heat, the hotter the water and the more steam escapes. Hot gas in galaxy clusters behaves much the same way. But in small galaxy groups, this "steam" leaks out faster than you'd expect from the temperature alone.

The Universe was born in the Big Bang and almost instantly passed through a phase of inflation — an ultra-fast expansion that blew up microscopic regions to cosmological scales.