If the Ricci curvature of a complete noncompact Riemannian manifold is asymptotically nonnegative, then the essential spectrum of the Laplacian on functions is the set of nonnegative real numbers.  When we consider the Laplacians on p-forms, much stronger assumption is needed. We prove that if the manifold is asymptotically flat, then the spectra of p-forms are connected sets of the real line. This is joint work with N. Charalambous.