Kouichiro Nakanishi

In the Antennae Galaxies, which are crashing into each other, giant gas clouds collided at a speed of 50 kilometers per second. It's like two trains hurtling toward each other — the impact compressed the gas, and it ignited with new stars.

A filament of the cosmic web stretches through the young universe, and strung along it like beads on a necklace are galaxies. In the core of the SSA22 protocluster, which in a few billion years will become the center of a massive cluster, these beads are still hot and dusty: stars are being born inside them, and cold gas serves as fuel.