M. Mori

A bus schedule drifts: if you don't check it, you'll miss your ride. Planets around other stars have the same problem – their crossings of the star's disk gradually shift. The ExoClock project pooled 30,000 observations from Earth and space to refine the schedule for 620 distant worlds. For 45% of the planets, transits were found to be off by hours.

When a star like the Sun ages, it swells and sheds its outer layers. What remains is a small, dense white dwarf — the former core. Around it, planetary debris can remain: rocks, dust, even whole asteroids. They orbit like a carousel that's been taken apart, but the pieces are still spinning. Astronomers watched the white dwarf WD 1054-226 for six years.

Cosmic rays are not light but charged particles bombarding Earth from all directions. Most of them are protons (hydrogen nuclei), but heavier nuclei also show up: helium, nitrogen, iron.

Deep beneath Japan's Mount Ikeno sits a tank holding 50,000 tons of the purest water. Inside, it catches neutrinos — ghostly particles that zip through Earth as if it weren't there. When a star explodes in our galaxy, neutrinos arrive first, hours before the light.

Inside every atom lives a proton. For a long time, it was considered as eternal as matter itself. But theories that unify all forces of nature predict that, sooner or later, the proton will decay. The only question is how long we have to wait. In the Japanese detector Super-Kamiokande — a giant tank of ultra-pure water — physicists searched for signs of such a decay.