  The dark photon, an new hypothetical light spin 1 field, constitutes a
well-motivated dark matter candidate. It manifests as an oscillating electric
field with a fixed direction, which can be observed in magnetometric records.
In this letter, we use magnetometer data from the Voyager probes to look for
the dark photon in the 10^-24 eV to 10^-19 eV mass range, corresponding to
frequencies between 10^-9 Hz and 10^-4 Hz. We also discuss the sensitivity of
possible future SQUID magnetometry experiments.
