We have described the relationship between the fractional Fourier transform and the Wigner distribution by using the Radon-Wigner transform, which is a set of projections of the Wigner distribution as well as a set of squared moduli of the fractional Fourier transform. We have introduced the concept of fractional Fourier transform moments and have proposed a way for the calculation of the well-known global and local moments of the Wigner distribution, based on the knowledge of a few fractional power spectra. The application of the results in optics and signal processing has been discussed briefly.