WE CALL it home, but in some ways we know less about the Milky Way than about neighbouring galaxies. Trying to determine what it looks like has been like trying to identify the structure of a forest while sitting in it. A map of our galaxy’s spiral arms should redress the balance.
Evan Levine and his colleagues at the University of California, Berkeley, created the map of the outer part of the galaxy’s spiral arms using radiotelescope measurements of the amount of atomic hydrogen in the galaxy from the joint Leiden/Argentine/Bonn survey.
The team confirmed that the galaxy has a…
