  It is possible that bosonic dark matter forms halos around the Sun or the
Earth. We discuss the possibility of probing such halos with atomic clocks.
Focusing on either a Higgs portal or photon portal interaction between the dark
matter and the Standard Model, we search the possible parameter space for which
a clock on Earth and a clock in space would have a discernible frequency
difference. Bosonic dark matter halos surrounding the Earth can potentially be
probed with current optical atomic clocks.
