Galaxies rotate once per billion years say astronomers

Space and time on a universe scale are much larger than humans can really comprehend. We can understand the spinning of a clock each day, but what's harder to comprehend is that galaxies spin just like a clock. According to astronomers, the galactic clock spins very slow.

Astronomers have discovered that all galaxies, no matter how large or small, rotate once every billion years. The scientists point out that we aren't talking the precision of a Swiss watch, but it would take a person sitting on the extreme edge of a galactic disk about a billion years to make one revolution.

Professor Gerhardt Meurer says that simple math shows that all galaxies of the same size have the same average interior density. He also says that you won't find a denser galaxy rotating faster or a lower density rotating more slowly. Scientists say that this regularity in galaxies helps to understand the mechanics that make a galaxy tick.

The astronomer says that his team expected to find only newly formed stars at the edge of the galactic disk, but they also found older stars at the edges. He says that this work has shown that galaxies rotate once per billion years, have a sharp edge populated with a mixture of interstellar gas, old and young stars.

Meurer also says that the next generation of radio telescopes, such as the Square Kilometer Array, will be able to generate "enormous" amounts of data. Thanks to scientists now knowing where the edge of a galaxy lies, the processing power needed to search through the data will be reduced.