This paper initiates a series of works dedicated to the rigorous study of the precise structure of gravitational radiation near infinity.We begin with a brief review of an argument due to Christodoulou [1] stating that Penrose's proposal of smooth conformal compactification of spacetime (or smooth null infinity) fails to accurately capture the structure of gravitational radiation emitted by N infalling masses coming from past timelike infinity i − .Modelling gravitational radiation by scalar radiation, we then take a first step towards a rigorous, fully general relativistic understanding of the non-smoothness of null infinity by constructing solutions to the spherically symmetric Einstein-Scalar field equations. Our constructions are motivated by Christodoulou's argument: They arise dynamically from polynomially decaying boundary data, rφ ∼ |t| −p as t → −∞, on a timelike hypersurface (to be thought of as the surface of a star) and the no incoming radiation condition, r∂ v φ = 0, on past null infinity. We show that if the initial Hawking mass at past timelike infinity i − is non-zero, then there exists a constant C = 0 such that, in the case p = 1, we obtain the following asymptotic expansion near I + , precisely in accordance with the non-smoothness ofSimilarly, if p > 1, we find constant coefficient logarithmic terms appearing at higher orders in the expansion of ∂ v (rφ).Even though these results are obtained in the non-linear setting, we show that the same logarithmic terms appear already in the linear theory, i.e. when considering the spherically symmetric linear wave equation on a fixed Schwarzschild background.As a corollary, we can apply our results to the scattering problem on Schwarzschild: Putting smooth compactly supported scattering data for the linear (or coupled) wave equation on I − and on H − , we find that the asymptotic expansion of ∂ v (rφ) near I + generically contains logarithmic terms at second order, i.e. at order r −4 log r.