Galactic corona

The galactic corona (not to be confused with the sun's corona; also called the dark matter halo) is a region of space surrounding the galactic halo of spiral galaxies, including the Milky Way Galaxy that consist mostly of dark matter.

Description

The corona is the single largest part of the Galaxy as it covers the space between 100,000 light-years to 300,000 light-years from the galactic center. It is also the most mysterious part of the Galaxy. It is now believed that as much as 90% or more of the Galaxy is composed of dark matter, a type of matter that does not seem to interact with the rest of the Galaxy's matter and energy in anyway except through gravity. The corona is the location of nearly all of the Galaxy's dark matter, which is more than ten times as much mass as all of the visible stars, gas, and dust in the rest of the Galaxy. The corona is likely to include more than 1,000,000,000,000 solar masses of dark matter, thus the Milky Way Galaxy may have a mass of 2,000,000,000,000 solar masses.

See also

• Galaxy formation and evolution