Galaxies are classified on the basis of the arrangement of stars - they form a shape like a spiral, disk, or sphere. The Milky Way or the spiral galaxy is home to our own solar system, and the planet Earth.

Our galaxy is called the Milky Way because of how it looks in the night sky. As many famous astronomers have said, the Milky Way looks like a stream of milky glowing stars.

The Milky Way is over 13.2 billion years old (about the age of the universe itself) and consists of about 200 to 400 billion stars. It has fascinated humans for many millennia, and will continue to do so in the future because it possesses some intriguing properties.

The Milky Way, as already mentioned, is an elegant spiral-armed galaxy. A spiral galaxy consists of a ball-shaped body with swirling arms surrounding it.

There is very dense celestial matter at the core of the galaxy, and the stars become less crowded going down the arms. Our sun and the solar system are located in one of the arms of our galaxy.

The galaxy itself rotates around its center, completing one rotation in just over 220 million years. Now that, my friends, is a very long period when compared to the earth's rotation period of 1 day.

New reports are coming out that suggest that the common perception of the Milky Way's structure may not be correct. However, mapping the Milky Way is very difficult, since we are looking at it from the inside, with many stars blocking views of the core of the galaxy.

New research shows that the galaxy is missing two of the four arms that it was thought to have. This research has forced most of our scientists to reconsider their perception about the galaxy. Two research teams have carried out studies very recently, giving some amazing results.

The first team used the Spitzer Space Telescope, which can see through dust and successfully map the orbital speeds of the stars. Two astonishing results that were brought out were that two of the galaxy's four arms are in fact just small side branches, and the central core is almost twice in size that was previously believed!

The other team utilized such a powerful telescope that you may even be able to read newspaper on the moon sitting here on earth. There, the research shows that the galaxy is moving in a much different manner than what we thought it to be.

Change in the pattern of the motion leads to a change in the shape gradually, which scientists can use to backtrack and make better guesses about the origins of the Universe. It also helps us in having a better understanding of spiral galaxies like the Milky Way and its nearest neighbor, the Andromeda galaxy, and galactic motion in general.

However, it may be a long time before we can say that we have substantial information about galaxies and the universe in general, because there is so much more to learn!