L. Gu

The MicroBooNE detector is a large tank of liquid argon that catches particles flying through it. When a particle passes, it leaves a trail of charge and a flash of light. These trails combine into a three-dimensional picture of the event, as if the particle were drawing its path in a transparent cube.

Neutrinos are tiny particles that zip through Earth, barely noticing it. In the MicroBooNE experiment, they are caught in a tank of liquid argon. When a neutrino strikes an argon nucleus, it produces an electron and protons, like splashes from a stone thrown into water.

The XRISM X-ray telescope spent 170,000 seconds staring at the core of galaxy Cygnus A — one of the most powerful radio sources in the sky. At its center lurks a supermassive black hole that sucks in matter and heats it until it glows in X-rays. The instrument caught light from iron atoms that had lost electrons.

A chamber the size of a small truck is filled with liquid argon at minus 186 degrees Celsius. When a particle flies in, it knocks electrons off argon atoms, and those electrons drift toward the walls, tracing a three-dimensional picture of the event.

The hot gas in galaxy clusters shines in X-rays, and a significant portion of that light comes from iron atoms that have lost many electrons. These atoms leave characteristic bright lines in the spectrum, like fingerprints. Astronomers use them to determine the temperature, density, and motion of the gas.