  Collisional threats posed by Near-Earth Objects (NEOs) are increasingly being
confirmed by National Aeronautics and Space Administration (NASA) and European
Space Agency (ESA) sky surveys. Efforts to develop tools to perform modelling,
analysis and prediction of possible future impact events are ongoing. The aim
of this research is to design a model for Large Earth impact events, describing
atmospheric entry, ground impact and post-impact dynamics for impactors large
enough to cause harm to the Earth. We present results of Large Earth Impact
(LEI) events involving a number of objects with densities ranging between $1000
- 8000 kg m^{-3}$. We use Python code to solve differential equations and
perform calculations on analytical models built into the collision simulation
algorithms while feeding relevant physical input in terms of object velocity
and diameter. We find that denser impactors have slower rates of decrease in
momentum while hitting the atmosphere. The denser impactors which exhibit
greater resistance to atmospheric disruption result in more energetic ground
impacts events in terms of crater formation, thermal radiation generation,
seismic effects, ejecta displacement and air-blast effects. We conclude that
impacting objects with high masses maintain greater kinetic energies compared
to objects with less mass thus posing greater collisional threats to the Earth.
