  Gravitational Wave (GW) astronomy promises to observe different kinds of
astrophysical sources. Here we explore the possibility of detection of GWs from
hyperbolic interactions of compact stars with ground-based interferometric
detectors. It is believed that a bound compact cluster, such as a globular
cluster, can be a primary environment for these interactions. We estimate the
detection rates for such events by considering local geometry within the
cluster, accounting for scattering probability of compact stars at finite
distances, and assuming realistic cluster properties guided by available
numerical models, their formation times, and evolution of stars inside them. We
find that, even in the conservative limit, it may be possible to detect such
black hole encounters in the next few years by the present network of
observatories with the ongoing sensitivity upgrades and one to few events per
year with the next generation observatories. In practice, actual detection
rates can significantly surpass the estimated average rates, since the chances
of finding outliers in a very large population can be high. Such observations
(or, no observation) may provide crucial constraints to estimate the number of
isolated compact stars in the universe. These detections will be exciting
discoveries on their own and will be complimentary to observations of binary
mergers bringing us one step closer to address a fundamental question, how many
black holes are there in the observable universe.
