Dark-matter satellite in stargazers' sight

[Jeffersons Ghost]

Milky Way's dark-matter satellite in stargazers' sights
By Jason Palmer Science and technology reporter, BBC News, Seattle

Scientists have proposed a means to track down the dark dwarf galaxies that should be orbiting the Milky Way, saying they have found evidence of one.

Spiral galaxies like ours have these satellites, but some are made of "dark matter" that is impossible to see.

The idea is to look for tracks they leave in hydrogen gas at the galaxy's edge, like the wake behind a boat.

Observations based on the idea suggest the existence of a far-flung satellite galaxy weighing up to 10 billion Suns.

http://www.bbc.co.uk/news/world-us-canada-12188642