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Stealth Galaxy

February 9, 2006

Some things are like dirt on your glasses–so close they’re hard to see. That’s why it’s taken so long for astronomers to identify what may be our closest neighbor galaxy.


A galactic merger. I’m Bob Hirshon and this is Science Update.

By building a 3-D map of our galaxy, astronomers have recently discovered what may very well be our nearest galactic neighbor. It’s so faint and so close that on a flat map of the sky it looks just like an average part of the Milky Way. But astronomer Robert Lupton of Princeton University says it’s actually a separate galaxy the Milky Way is slowly dragging in.

ROBERT LUPTON (Princeton University):
If you took a space ship and you waited a long time and you went out to a distance of 30 or 40 thousand light years away from the earth, then two out of every three stars would belong to this feature.

He says this neighbor will eventually merge with the Milky Way—and it’s probably not the only one. The 3-D mapping technique will likely reveal more small galactic neighbors.

I’m Bob Hirshon, for AAAS, the science society.