clipped from: www.abc.net.au   
Anna Salleh

The halo of stars surrounding the Milky Way is made up of two different parts that spin in opposite directions, according to an international team of astronomers.

Milky Way
findings could help settle a long-standing debate about how our galaxy and its halo formed
research could also help astronomers pin down much sought-after astronomical evidence of conditions just after the Big Bang
PhD student Daniela Carollo, based at Australia's Mount Stromlo Observatory in Canberra, and colleagues, report their findings today in the journal Nature
The Milky Way halo is a sphere of ancient stars, invisible to the naked eye, that surrounds the familiar flattened spiral disc of the galaxy
 

"We believe there are two main parts to the halo. It's not one simple halo," says Carollo's co-author and PhD supervisor Professor John Norris.

The researchers found inner and outer haloes, which rotate in opposite directions.

the inner halo is a flattened sphere rotating in the same direction as our sun but more slowly.