J. Köhler

The tiny star LHS 3844 is trembling. The invisible culprit is a rocky planet that whips around it every 11 hours. The planet pulls on the star, and the star responds with a barely perceptible wobble. Detecting that wobble is like noticing a 100-kilogram weightlifter step forward when a fly lands on his palm.

Cosmic rays aren't rays in the usual sense: they're fast particles bombarding Earth from all directions. Mostly they're protons and atomic nuclei. Their energies vary widely, from modest to fantastically huge. When such a particle heads our way and the Moon or Sun gets in its path, it gets absorbed.