  The local environment is ideal for searching out compact dark structures via
the microlensing and multi-frequency emissions as these objects are expected to
be faint and microlensing experiments have already hinted at their possibility.
In the case that these objects are composed of Dark Matter (DM) then there are
both few limits on their abundance but many consequences of their existence or
non-existence on both local and cosmic scales. In this work we examine the
possibility of Ultra-Compact Mini-Halos (UCMHs) formed in the early universe.
These objects can persist to the present epoch due to their large central
density inuring them to the worst effects of later tidal stripping. As such,
these objects could constitute probes of many details of early universe
physics, such as primordial phase-transitions, inflation, small scale
exploration of the primordial density perturbation field and non-Gaussianity of
these density perturbations. The fact that they are also highly dark
matter-dominated objects means that they are attractive objects of study in the
continuing hunt for the nature of Dark Matter (DM) through indirect detection.
Another reason to study such objects in the local environment is found in the
conjecture that encounters with UCMHs could induce catastrophic events on
planets within our solar system, e.g. mass-extinction events on Earth. We will
outline a strategy for multi-frequency UCMH searches within the region of the
Milky-Way in which Gaia can accurately reconstruct microlens masses. This
methodology ensures that any candidate UCMH DM emission should correlate to
some unidentified microlensing object with determinable mass and demonstrate
that large-scale volcanic extinctions on Earth due to UCMHs are unlikely but
that it is possible for loss of the Martian geodynamo to be driven encounters
with such compact objects.
