  In this paper we consider the use of wide field of view radar sensors such as
the Murchison Widefield Array (MWA), a low frequency radio telescope designed
for astrophysics and cosmology, for rapid response observations of the debris
clouds produced by collisions between objects in Earth orbit. With an
increasing density of objects in Low Earth Orbit, including legacy assets used
by the astronomy community over decades, the risk of new debris clouds forming
is also increasing. The MWA constitutes a wide field, rapid response passive
radar system and we explore its likely performance in the detection and
characterisation of debris clouds. In general, astronomy facilities such as the
MWA can play a role in protecting the space environment for the future. In
order to undertake this work, we adapt the NASA EVOLVE 4.0 breakup model,
utilising the EVOLVE outputs to produce representative dynamic debris clouds.
We find that the MWA is likely to detect a large fraction (>70%) of modelled
debris cloud fragments for collision masses between 100 kg and 1000 kg for
orbits in the lower part of LEO, if the MWA can achieve close to optimal
detection sensitivity. Useful detection fractions are still achieved for more
conservative assumptions. The detection fraction of fragments decreases as a
function of altitude and inversely with collision mass. Encouragingly, we find
that the wide field nature of the MWA allows the full evolving debris clouds to
be observed in a single observation, with only $\sim2\%$ of the debris
fragments escaping the sensitive portion of the field of view after 100
seconds, for all collision masses and altitudes. These results show that the
MWA is an intrinsically useful facility for the rapid characterisation of
debris clouds, but that work is required to achieve the data processing within
an appropriate timeframe to provide rapid alerts.
