  We study predictions for dark matter phase-space structure near the Sun based
on high-resolution simulations of six galaxy halos taken from the Aquarius
Project. The local DM density distribution is predicted to be remarkably
smooth; the density at the Sun differs from the mean over a best-fit
ellipsoidal equidensity contour by less than 15% at the 99.9% confidence level.
The local velocity distribution is also very smooth, but it differs
systematically from a (multivariate) Gaussian distribution. This is not due to
the presence of individual clumps or streams, but to broad features in the
velocity modulus and energy distributions that are stable both in space and
time and reflect the detailed assembly history of each halo. These features
have a significant impact on the signals predicted for WIMP and axion searches.
For example, WIMP recoil rates can deviate by ~10% from those expected from the
best-fit multivariate Gaussian models. The axion spectra in our simulations
typically peak at lower frequencies than in the case of multivariate Gaussian
velocity distributions. Also in this case, the spectra show significant
imprints of the formation of the halo. This implies that once direct DM
detection has become routine, features in the detector signal will allow us to
study the dark matter assembly history of the Milky Way. A new field, "dark
matter astronomy", will then emerge.
