Milky Way - Aakash Ganga

Milky Way (Aakash Ganga)

 Compared with other galaxies, our galaxy, the Milky Way, is relatively large. It measures approximately 100,000 light years across. The Earth and the rest of our Solar System lie about 28,000 light years from the middle of the Milky Way.

 Rotating spiral

 Most astronomers are convinced that the Milky Way is a spiral galaxy. Some, though, have suggested that it might be a barred spiral galaxy instead.

 Like all spiral and barred spiral galaxies, the Milky Way rotates. Closer to the middle it rotates faster than at its edges. Our Solar System revolves around the middle of the galaxy about once every 225 million years. According to this theory, the Solar System has only rotated once since the earliest dinosaurs walked the Earth.

 Seeing the galaxy

 On a clear night, you can see a broad, dense band of stars which stretches across the sky. In ancient times, people thought this band looked like a trail of spilled milk. This is how our galaxy gets its name. When you look along this band, you are looking toward the middle of the Milky Way.

 When to look

 In the northern hemisphere, the best time to see the Milky Way is between the months of July and September. It also looks impressive on dark midwinter nights.

 In the southern hemisphere, the Milky Way is seen at its most spectacular between October and December. This is when it looks most like a trail of spilled milk across the sky.