  New images of M31 at 24, 70, and 160 micron taken with the Multiband Imaging
Photometer for Spitzer (MIPS) reveal the morphology of the dust in this galaxy.
This morphology is well represented by a composite of two logarithmic spiral
arms and a circular ring (radius ~10 kpc) of star formation offset from the
nucleus. The two spiral arms appear to start at the ends of a bar in the
nuclear region and extend beyond the star forming ring. As has been found in
previous work, the spiral arms are not continuous but composed of spiral
segments. The star forming ring is very circular except for a region near M32
where it splits. The lack of well defined spiral arms and the prominence of the
nearly circular ring suggests that M31 has been distorted by interactions with
its satellite galaxies. Using new dynamical simulations of M31 interacting with
M32 and NGC 205 we find that, qualitatively, such interactions can produce an
offset, split ring like that seen in the MIPS images.
