F. Courbin

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.

Light from quasar PS J2305+3714 has been traveling toward us for more than eleven billion years. On its way, it passes near a massive galaxy whose gravity bends its path, like a heavy ball denting a stretched sheet. Through a telescope, we see not one quasar but two images — two points of light that are actually the same distant object.

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.