Today, particle physicists are able to probe the properties of matter particles on earth up to an energy resolution of a few TeV. The Large Hadron Collider (LHC) at the CERN is in this sense the best man made microscope. Besides, processes of even higher energy are relevant for astrophysics. For example, ultra high energetic (UHE) cosmic gamma rays are known to reach energies of the order of 1016 eV.
Quantum Gravity effects will be relevant at the Planck scale, that is at about 1019 GeV. This is the energy at which the Compton wavelength of a lump of energy such as an elementary particle equals its Schwarzschild radius which then would force the particle to become a black hole. Still 16 orders of magnitude away from the LHC energy scale, the astroparticle energy scales differs only by 9 orders of magnitude from the Planck scale. But still, one might think that Quantum Gravity effects will not play any role for probable physics i.e. elementary particle physics. However, during the very early times of the Universe, particle processes might be highly effected by Quantum Gravity. Remnants of such interactions probably affect cosmological observables, which might be measured in the foreseeable future.