We report the detection of continuous microhertz waves originating from Jupiter, recovered from two decades of atmospheric pressure measurements across Germany. Barometers act as largeu2011aperture antennas for lowu2011frequency signals, allowing coherent recovery of a carrier near 55.97 $mu$Hz, which corresponds to twice the rotation frequency of Jupiter’s solid core. A directu2011conversion receiver iteratively compensates all known phase modulations caused by Earth’s orbit and the four Galilean moons, concentrating the wave’s energy into a narrow spectral line with a signalu2011tou2011noise ratio of 100. We measure the longu2011term frequency drift of Jupiter’s core and determine the modulation indices associated with each moon. The phaseu2011modulation pattern is stable across 318 independent realizations. Additional spectral features indicate that Jupiter hosts multiple internal oscillators with distinct frequencies. These results demonstrate that Earth’s atmosphere responds coherently to microhertz waves generated by nearby planets.