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A light-year is the distance light travels in one year. It is 9.5
trillion (9,500,000,000,000) kilometers. The size of a galaxy may be
as little as a thousand light-years across or as much as a million
Galaxies are labeled according to their shape. Some galaxies are called "spiral", because they look like giant pinwheels in the sky. The galaxy we live in, the Milky Way, is a spiral galaxy. Some galaxies are called "elliptical", because they look like flat balls. A galaxy may be called "irregular" if it doesn't really have a shape. A new type of galaxy was discovered recently, called a "starburst" galaxy. In this type of galaxy, new stars just seem to 'burst out' very quickly.
Which type of galaxy looks like a giant sky pinwheel?
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