The mystery of spiral galaxies and their mysterious sleeves

Astronomers have discovered the largest recognized spiral galaxies and they have identified the "skeleton" of the Milky Way. Our own Milky Way, most likely, is a spiral galaxy. Indeed, our solar system and the Earth are somewhere close to one of his whiskers, pulled back the sleeves.

And almost 70% of the galaxies closest to the Milky Way are a spiral. But despite their general morphology of galaxies, such as our form and retain their characteristic features, which remains a puzzle in astrophysics. Are their sleeves in spiral galaxies? Whether they can appear and disappear over time?

Classification of meteorites

While there are different classifications, one of the most important is the collecting feature of composition and origin of meteorites. In this division we find:

1) Primitive: is the most primitive material in the solar system (they have several billion years) that have remained virtually unchanged since they formed, ie never suffered melting or differentiation processes.

The universe is older than before idea

The European Planck spacecraft has gained the most accurate and detailed map ever made ​​of the oldest light in the universe. The results of this map suggest that the universe is expanding more slowly than scientists thought, and that is 13,800 million years, 100 million years older than previously believed. The data also show that in the universe there is less energy and dark matter than previously known.