A recent breakthrough has been made in the study of the outskirts of galaxy clusters. By combining XMM-Newton observations of X-ray surface brightness with pressure measurements obtained by the Planck observatory using the Sunyaev-Zel'dovich effect, it has become possible to obtain measurements of cluster thermodynamics in regions which are too faint for accurate X-ray spectroscopy with XMM alone. However, the spatial resolution of such studies is limited by Planck's poor PSF (a FWHM of around 10 arcmins). Simulations of galaxy cluster formation predict that clusters become increasingly asymmetric in their outskirts as they connect to the cosmic web, with dramatic variations in temperature and entropy. In this talk, I will discuss the thermodynamic properties of the intracluster medium out to the virial radius of the Coma cluster, one of the nearest massive clusters in the universe, using a large mosaic of XMM-Newton observations. Taking advantage of new XMM-Newton observations towards the Coma cluster, the outskirts region of the intracluster medium is investigated in detail, where within this region the intracluster medium is expected to be virialised, and outside of which matter is still accreting onto the cluster as it continues to form.