NASA's Goddard Space Flight Center: The galaxy, NGC 178 may be small, but it packs quite a punch. Measuring around 40,000 light-years across, its diameter is less than half that of the Milky Way, and it is accordingly classified as a dwarf galaxy. Despite its diminutive size, NGC 178 is busy forming new stars. On average, the galaxy forms stars totaling around half the mass of the Sun per year -- enough to label it a starburst galaxy.