User:Mihir 179/sandbox

′′′MILKY WAY′′′ [[Category:]]″LOCATION″

A glance up at the night sky reveals a broad swath of light. Described by the ancients as a river, as milk, and as a path, among other things, the band has been visible in the heavens since Earth first formed. In reality, this intriguing line of light is the center of our galaxy, as seen from one of its outer arms.

Understanding the structure of the Milky Way has long been challenging. The solar system sits on the outer edges of one arm in a disk of material, and no one can see across the dense center to the other side.

"The sun's location within the dust-obscured galactic disk is a complicating factor to observe the galactic structure," Denilso Camargo, of the Federal University of Rio Grande do Sul in Brazil, said in a statement.

The Milky Way is a barred spiral galaxy, about 100,000 light-years across. If you could look down on it from the top, you would see a central bulge surrounded by four large spiral arms that wrap around it. Spiral galaxies make up about two-third of the galaxies in the universe.

Unlike a regular spiral, a barred spiral contains a bar across its center region, and has two major arms. The Milky Way also contains two significant minor arms, as well as two smaller spurs. One of the spurs, known as the Orion Arm, contains the sun and the solar system. The Orion arm is located between two major arms, Perseus and Sagittarius.

The Milky Way does not sit still, but is constantly rotating. As such, the arms are moving through space. The sun and the solar system travel with them. The solar system travels at an average speed of 515,000 mph (828,000 km/h). Even at this rapid speed, the solar system would take about 230 million years to travel all the way around the Milky Way.