One of the most unusual galaxies known, Centaurus A, is pictured above. Cen A is marked by dramatic dust lanes that run across the galaxy's center. These dust lanes are so thick they almost completely obscure the galaxy's center in visible light. Our Milky Way Galaxy contains dust, but not in the same proportion. Cen A is also unusual compared to a normal galaxy because it contains a higher proportion of young blue stars, is a very strong source of radio emission, and has a unique structure. Cen A is thought to be the result of the collision of two normal galaxies.