The Milky Way Galaxy is most significant to humans because it is home sweet home. But when it comes down to it, our galaxy is a typical barred spiral, much like billions of other galaxies in the universe. Let's take a look at the Milky Way.
Our galaxy probably contains 100 to 400 billion stars, and is about 100,000 light-years across. That sounds huge, and it is, at least until we start comparing it to other galaxies. Our neighboring Andromeda galaxy, for example, is some 220,000 light-years wide. Another galaxy, IC 1101, spans as much as 4 million light-years. A key distinguishing feature of globular clusters in the Galaxy is their uniformly old age. Determined by comparing the stellar population of globular clusters with stellar evolutionary models, the ages of all those so far measured range from 11 billion to 13 billion years. They are the oldest objects in the Galaxy and so must have been among the first formed.Although most stars in the Galaxy exist either as single stars like the Sun or as double stars, there are many conspicuous groups and clusters of stars that contain tens to thousands of members. These objects can be subdivided into three types: globular clusters, open clusters, and stellar associations. They differ primarily in age and in the number of member stars.
informative!!
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