mers cannot test this theory on real galaxies. They can, however, run simulations on computers programmed with the basic laws of physics. Such simulations have shown that certain kinds of interactions can cause immense amounts of gas to build up, triggering a starburst in the center of a galaxy—precisely what we see in Maffei 2. These simulations, together with Maffei 2’s irregular shape, argue for its recently having interacted with another galaxy.